Dewey is free to his opinion, but documentation that the newer ultrasound devices are more accurate than the pin and gauge tools would require comparison of both techniques on multiple barrels.
When Bill Henry made my tool, he also made a standard segment of .038" thickness with which I could 'zero' the gauge, and could (and do) recheck frequently during the measuring process. If my gauge has been set to the .038" 'zero', repeatedly measures the wall thickness at the same number (say .045 at 9"), and when checked is still set at .038" I believe the measurement is accurate. Flexing of the round support bar does not seem to be relevant to the relationship between the pin on the bar and the pin of the gauge, unless I contact the barrel wall with the bar.
I can't comment if the new high resolution US devices can detect defects within the wall of fluid steel or pattern welded barrels.
The problem with RT is in differentiating surface defects (pits) from defects within barrel
A few smiths and NDT labs have examined pattern welded barrels, but there are no industrial standards for the interpretation of those tests. Both MPI and RT might be helpful to show microscopic through cracks in a pattern welded tube. Obviously a great deal of research would need to be performed to determine if US can find hidden defects/voids/inclusions in pattern welded tubes, but the industrial money is not in testing a few vintage shotgun barrels.
Bottom line: if you want assurance as to the safety of your barrel, beyond a bore scope exam and expert wall thickness measurements, have them proved at a pressure of 1 1/2 X the pressure of the load you intend to use. And there are testing labs in the U.S. that will do that.
I remember a recent thread in which a member found to his horror that the minimum wall thickness of a gun made for him in Europe in 1972 (?) was only 7 thou.
Assuming that no work had been done on that barrel since it was made it appears to have survived both Proof and just on 50 years of at least intermittent use without even bulging.
As there is no definite minimum thickness at which a barrel will/will not fail it is perhaps less important to worry whether the gauge is producing a reading to the nearest thou, than to regard what it shows as a “ball park” figure to show if the minimum figure is adequate, marginal or “buyer beware”.
would be nice to hear from members here, re their opinions regarding minimum barrel wall thicknesses in front of chambers, for modern fluid steel barrels...
I use a cheapo one from Brownell's and my measurements have been confirmed on Hosford or similar gauges. I simply allow the gauge to flex vertically before/while zeroing the gauge.
The measurements don't need to be precise, I just need to know within a few thousandths what I am dealing with. The thinnest I have seen so far was my 12 proved 10 gauge that had been hogged out to a .783 bore. Still had .021 at the thinnest spot.
dan, telling us what the thinnest measurement is, is of little value, without telling us where that thinnest point is...
and barrel wall thickness in front of the chambers and perhaps incremental measurements 16 inches or so up from there, is what is really important for safe shooting...
They are commonly in use in industrial piping environments.
Because, when things flow through a pipe, they wear it out from the inside, leading to leaks, big, and small. So, they are pretty common.
I’ve seen two types, one type connected to a computer screen, and one type just touched on the surface.
On the computer screen one, the operator move the transducer back-and-forth, and identified very precisely where the voids were behind the surface.
What I am trying to say, is that the people using the tool are not super geniuses, but the tools work very well, so the learning curve isn’t long, and doesn’t require complex fixturing or technique.
I make my own wall thickness gage similar to the one Drew has in his post. I have verified its reading via other methods such as cross sectioning ultra sonic and eddy current. They all give the same reading within .0006" which wouldn't make the slightest difference.
What is really important? Accuracy and repeatability. If you get the "right" number, then it does not matter. Being able to check and verify that number over and over again gives you a bit of confidence. I have been using my setup for 20 plus years and checked it against known samples hundreds of times. When ever I find a thin area, I get real careful, but when going over a set of barrels, as long as the thickness is measuring above .025- .030 and is the same as areas nearby, I do not worry too much. If I find a area which is thinner than areas nearby, then I start looking for dent repairs and think about file work to blend the repair. If my setup is off .001-.005 I do not care as long as the walls are .025-.030+. I shoot several guns with barrels .020 as longs as the thin area is well towards the muzzle. But is is location and repeatability which my setup gives me consistently which is what I need. I know it is accurate because I have used it for decades and verified it with multiple other systems. We can not all be off the exact same way and same amount. Potential minor variations are not critical when you are talking about barrels not near a critical thinness. Mine are not. If I got to the point that .0006 was important then I would find a new gun.
The question about wall thickness just in front of the chamber was important to me, as I have a couple great old guns that have been lengthened from 2 1/2" to 2 3/4" chamber without reproofing. One was done by a very reputable gunsmith operation and they assured me it was safe to use. Both are over .100 right in front of chamber. I was doing research and found in one of Gough Thomas's books where he measured pre war English doubles and post war Italian, Spanish and Japanese guns. The English were from .106 to .122 with several in the .113 range. The post war doubles were .076 to .086. He also discusses elastic limits and a safety factor of 2, states a gun with working pressure of 3 tons should be .084.
This ain't a dress rehearsal , Don't Let the Old Man IN
I always use my gauges vertically. I have both the Manson style mounted to a wall and also have the British style wall thickness gauge, the type you’d find in most British & continental gunmakers shops. I much prefer the latter. My mitutoyo dial indicator is as good as it gets, and the readings when using that very rigid British style gauge are dead accurate and repeatable. If the gauge your using works correctly and you’re getting accurate readings, it doesn’t matter what type it is. I much prefer the British style gauge over the Manson though, but that’s just me.
Thanks for that data Nitrah. The difference in Thomas' MWT recommendation is very likely related to barrel composition, and possibly service load pressure standards at the time of proof. Turn-of-the-century pattern welded vs. decarbonized vs. pre-WWI Siemens-Martin 1030 vs. 1940s 4140 matters.
In 1925, the British 2 1/2” & 2 5/8” 12g maximum service load was reduced from 1 1/4 oz. 3 1/4 Dr.Eq. to 3 Dr. Eq. with 1 1/8 oz. shot with a mean pressure of 3 1/4 tons by LUP = 9,800 psi by Burrard’s conversion. The 2 3/4” 12g max. service load was then 3 3/8 Dr. Eq. with 1 1/4 oz. shot with a mean pressure of 3 1/2 tons = 10,640 psi by Burrard’s conversion. (Primarily for heavier “Waterfowl” guns)
And that is why it is difficult to provide generalized wall thickness recommendations.
Slightly OT, but not worth a stand alone thread....
What are the nominal wall thicknesses for a 10ga? I see lots of info for 12ga, but not much for 10. I’d imagine the pressures (all things equal and applying common sense to loads) would be slightly less.
I've only seen one period 10g pressure report; from DuPont Brandywine Experimental Station data cited by Charles Askins in 1933 DuPont Bulk Smokeless Powder (not Oval used for the Super-X loads). 10g 4 1/4 Dr. Eq. 1 3/8 oz. shot = 10,662 psi + 10-14% for modern piezo transducer numbers
And have a single 10g measurement; a Smith hammer gun with Twist barrels Bore .798" End of chamber L .174" and R .167" 9" from breech L .095" and R .092" 9" from muzzle L .052" and R .050"
Mr eightbore,,,i think it's a Manson I always check vertically , the mwt could depend on the steel I have some krupp barrels that are .80 in front of the chamber and 30 9 inches from the muzzle I have some old heavy barrels that are much thicker
Found a couple more 10g in my files measured by a friend; both 3 frame pattern welded Parkers and both with bores .794" #1 end of chamber .140"; 9" from breech .093" and 9" from muzzle .050" #2 .114"; .059" and .040"
All the below had standard bores and chamber length and were felt to be unaltered
End-of-chamber: 3 No. 1 1/2 frame 12g fluid steel Parkers were .088", .092" and .105"
4 No. 1 frame 16g fluid steel Parkers were .084", .100", .105" and .111"
No. 0 frame 16g fluid steel Parker .104" L and .099" R
A No. 0 frame 20g fluid steel Parker was .091"
http://parkerguns.org/forums/showthread.php?t=31521 12 gauges Baker Paragon L-.97, R-.103 2 5/8" chamber Win 21 L-.115, R-.119 2 3/4" chamber LC Smith Field L .102, R .105 2 3/4" chamber Parker PH L .107 R .115 2 1/2" chamber, 1 frame Parker VH L .90, R .90 2 5/8" chamber, 1 1/2 frame
Some time back, I posted a description of the horizontal method of measuring wall thickness with a Manson gauge. This is not a recommendation, only a different method. By the way, Mr. Hosford kindly demonstrated the horizontal method to me, yes, on a Manson gauge. Previously, I had been using the vertical method. The drawback of the vertical method is that it is impossible to use at a gun show table. With a helper to hold the barrels in place, the horizontal method can be used on a table.
Mr eightbore you can put the but of the gun on the ground have Mr seller or buyer hold the gun check from the muzzle .you can check from the breech by taking the barrels off but if you get acceptable results your happy with checking horizontal then that's what you should use
doc drew, thanks for sample measurements...they seem to validate my 90/30 standard, as passed on to me by old ed, the gunsmith...who has also passed on...i am sometimes lost without the confort of having access to his knowledge and wisdom...
G.T. Garwood (Gough Thomas) Shooting Facts and Fancies, Chapter 34, 1978 Gives an average of .114” for end-of-chamber wall thickness for mid-20th century English 12g guns, but observes that higher tensile strength steel allows for lower wall thickness.
Jack Rowe demonstrates use of a vertical gauge starting at 2 minutes. He states his lower limit is .020”, but clearly in reference to the distal 1/3 of barrel and he never addresses end-of-chamber wall thickness.
Apparently, some Brit guns (i;e;: 2" 12b guns) were built with barrels as thin as .018, sometimes less. So they were proofed and left the factory with barrels less than 20 thousandths of an inch. It all depends on the intended use and, of course, on passing proof spec for the cartridge designated.
As Jack Rowe states in his video, the measurement 9" from the muzzle is usually the thinnest, where the pressure has diminished significantly with a nitro cartridge. So, a gun might have .015" thickness at that point, or perhaps less, and still pass proof, but it would dent very easily and would not be thick enough to safely repair the dent.
My main 'smith, Pete Mazur, uses an ultrasound thickness detector. Interesting to watch - a lot like a medical ultra sound procedure.
C Man Life is short Quit your job. Turn off the TV. Go outside and play.
no one else here or anywhere else for that matter, seems to make a big deal about barrel wall thickness in front of chambers...
come to think of it, of the hundreds of doublegons that i have sold over the years, i do not recall any one asking about the barrel wall thickness in front of the chambers...
maybe my concerns about shooter safety are much to do about nothing?
and now we learn from jack rowe, that only .020 9" down from the muzzles is ok...
so, logic says to stop measuring barrel walls, cause hit dont make no difference no how?
although... once had a 12 gauge churchill box lock that had been sleeved...beautiful gun, beautiful sleeving job...only way one could tell that it was sleeved, was by the "sleeved" stamps on the barrel flats...however, the barrel walls in front of both chambers were only .060...per old eds advise, i reluctantly sent it back...at the time i was afraid to shoot it...wonder if i did seller a dis service?...
and now im wondering if my concern about opening chambers on light 2 1/2" european made guns is also, much to do bout nuttin?
mebbe we should jes open erm awl up to 2 3/4 an be dun wid hit...shore wood solve duh short shell shortage problem, wouten hit...
ah mean, like who the hell needs rst any mo, any how...an when the action loossens up an the wood cracks, we could jes peen, shim, and glue her up, an keep on shootin...
I'd like to thank the Preacher for his link to Dewey's Blog. I also recall that the Preacher has, in the past, also posted photos of his own Bill Henry dial indicator tool being used in a horizontal orientation.
Most folks seem to understand and agree that this type of tool is less prone to error or false readings when used vertically.
Originally Posted by Drew Hause
Flexing of the round support bar does not seem to be relevant to the relationship between the pin on the bar and the pin of the gauge, unless I contact the barrel wall with the bar.
Since the pin on the bar is pressed or screwed into the bar, it stands to reason that any undue lateral pressure on that pin will cause some slight deflection of that bar. Dewey didn't just make an unfounded statement concerning that potential error. He actually provided a detailed explanation, along with a short video showing just how much a tool steel bar can and will deflect when a lateral force was applied. He even used a trigger gauge to show us just how much force was applied to cause the deflection seen on his dial indicator.
Talk is cheap. Dewey backed up his talk with graphic video evidence. I didn't need such evidence to prove what I already know, because I have had to use a steady-rest on my own lathe when turning longer pieces of round steel stock, to prevent deflection during turning. I have also seen long steel line shafts or mandrel bars, up to 10 inches in diameter, flex SEVERAL INCHES under their own weight when lifted by a crane at their mid-point. I didn't need any dial indicator to see that long solid steel bars are quite flexible. The flexible nature of steel is also seen in seemingly rigid torsion bars.
I even worked with a guy who lost his left testicle when he unwisely decided to spin a stainless stainless steel rod in a 3600 rpm three jaw chuck polisher. The unsupported rod abruptly flexed enough to partially castrate him as soon as he applied lateral pressure with a piece of emery cloth. Ouch! Glad I didn't get to see that one.
It is also common knowledge that if you gave five guys five micrometers, or dial, or digital vernier calipers, and they measured the exact same item, they would likely get several slightly different measurements. This is why Machinist and Tool & Die Apprentices are taught proper measuring technique to minimize errors. I remember my High School Shop Class teacher showing us how the same measuring tool could give very different readings when used improperly. That potential operator induced measuring error is compounded with a trickier setup, such as trying to measure barrel wall thickness down deep in a shotgun barrel by using a long measuring instrument that can and will flex slightly under various lateral pressures.
That said, I would agree with those who feel that despite the known potential for error, a careful and skilled hand could use one of these tools to obtain reasonably accurate measurements. And let's face facts... the majority of shotgun barrels are not honed dangerously thin. So a slight measuring error is unlikely to put someone into a dangerous situation. Of course, no matter what sort of tool is used to measure barrel wall thickness, calibration before use is very important. And should readings on the thin side be found, especially at the points where pressure is still high, and eyeballs or fingers are in close proximity, then extreme caution, and/or a qualified second opinion should be sought before using the gun.
Originally Posted by ClapperZapper
I have never used one to measure shotgun barrels.
They are commonly in use in industrial piping environments.
Because, when things flow through a pipe, they wear it out from the inside, leading to leaks, big, and small. So, they are pretty common.
Actually, the Ultrasonic Measuring equipment is rarely used to measure pipes or tubing after it wears out. That wear is more commonly detected when it begins to leak or abruptly ruptures. Then it is simply scrapped and replaced. But it is very commonly used in industry to measure wall thickness and find defects before the new product is shipped to the customer. My own experience with Ultrasonic and other Non-Destructive Testing (NDT) equipment was mentioned on page 3 of the "Wiggle in the Barrels" Thread. I have repaired them and/or made logic changes or edits in the PLC programs, but never worked as an Ultrasonic NDT operator. Companies wishing to cover their butts and avoid liability spend big money to purchase and maintain NDT testing equipment, so I assume they are better than the older and less efficient mechanical measuring systems.
Keith you are an idiot get back to me when you correct edds "igorant" replys.after hearing your rants for a long time I don't think anyone except edd cares what you have to say you sir Are a turd in the punch bowl
I found Bill's protocol from 2012, with additional discussion http://parkerguns.org/forums/showthread.php?t=7889&page=5 1. My gauge has a 5/16" hole in the "block", so I installed an eye bolt in the hole with the eye facing out. 2. I tied a generous loop of clothesline rope to the eye bolt with loops and knots to make holding on easier. 3. You need an assistant if measuring at a gun show or auction. The assistant needs no skill or strength. 4. The assistant will hold the barrels steady on a table with a cushion and the end to be measured over the edge. An assistant is to be preferred over a vise or weights, especially at a show or auction. No weight is heavy enough to hold the barrels steady. 5. The micrometer is zeroed with the rope holding one end horizontally and the ball supported at the other end by the fingers. 6. With the micrometer properly zeroed, the ball end is inserted into the barrel, run from the open end of the barrel to the extent of the rod and the results recorded. The rod must not contact the interior barrel wall for accurate results. 7. The assistant will rotate the barrels on the pad 90 degrees and the results recorded as in the previous instructions. 8. Another 90 degree rotation will complete the measurement of that end of that barrel. The fourth quadrant cannot be measured. 9. Do the same to the other barrel. 10. Reverse the direction of the barrels and do the same from the other end. This should result in 12 recorded minimum thickness measurements from one set of barrels.
I put 25# in the box in which I carry the gauge, and use bungie cords to affix the barrel. I can rotate the barrel while watching the gauge, but do need an assistant to record the results
And thank you dblgnfix for this post, which William apparently missed. I make my own wall thickness gauge similar to the one Drew has in his post. I have verified its reading via other methods such as cross sectioning ultra sonic and eddy current. They all give the same reading within .0006" which wouldn't make the slightest difference.
Dr. Drew, thank you for posting my old post about how to use the Manson gauge in a horizontal position, either at a gun show or in your kitchen. If you read carefully, everything you need to know is in my post. Remember, it was taught to me by Jon Hosford, I didn't invent it. I was a machinist in training in my youth, but nowhere near as talented as Jon Hosford. It is about as simple a method for the use of the Manson gauge as you can find anywhere.
I have both the vertical gauge and the horizontal gauge. The vertical gauge is inherently not as accurate since one has to deal with the torque generated by the barrel not being measured. Even from a pulley hung in the ceiling the vertical measured barrel is subjected to the torque of the barrel to its side. The often seen brass “rest” on the vertical machines is just “for show” and the seller can manipulate the readings in front of the buyer. The horizontal machine uses only gravity , which is a constant, to generate good readings. I lost a fine gun, sold to a friend , that I thought had thin barrels as measured with my vertical machine. His gunsmith remeasured the wall thickness with a horizontal machine and the barrels were well within the tolerance I would have accepted if I had only known. My vertical machine sits near the furnace, while the horizontal machine is on the workbench.
When using the horizontal machine by myself, I let a half filled bag of shot hold the barrels on the bench. It is easy to turn the barrels, held by the bag of shot, to any position.
I use the Manson gauge vertically,I have a spring on the arm that applies pressure to the ball machined on the end of the arm it works great .i can move the arm to 9.250 inches to eliminate some deflection
I have used Murph's "Hosford" horizontal technique with my Manson gauge for 10 years now and find it consistently repeatable within one or two thousandths. While experimenting with other ways to hold the block end, I realized that the cord in the eyebolt lets gravity do all the pulling and that the sensor ball naturally rolls to the bottom of the barrel without any side pressure influences from fixed holds on the block end. Thanks again Murph for saving me the cost of having to buy a Hosford tool, or one of Dewey's digital ultrasounds . MP
I measure horizontally and to hold the barrels I clamp a sawed off section of a broom handle tapered slightly at the end to jam into the chamber of one barrel. Firmly prevents barrel from turning until I want it to.
When an old man dies a library burns to the ground. (Old African proverb)
I did find this interesting reading especially in the way things have changed when I was purchasing guns here in the past. Especially if you did what I did was to purchase guns at local auctions with the best guns always being a farm auctions, these nearly always had the lowest prices though with the largest risk of coming away with a bad purchase. It was always caveat Emptor with no returns. Now a lot of guns where as you could say especially polished up for the event with barrels well reamed and polished for the occasion so you had to be able to spot them easily. My main interest was 12 bore because this was the most popular gauge here because smaller bores the cartridge where more expensive and not popular with the only exception was the .410. Now I am sure you all know that a tenth of an inch on this side of the pond can turn a gun from desireable to junk instantly. So to put the odds in my favour I would have two Gauge's that I built on the kitchen table one was a go no go bore Gauge with two interchangeable inserts .729 inch the standard 12 bore barrel diameter and the other .740 inch the end of the line for a 12 bore barrel having a 9 inch stop. The other Gauge was a short light pocket version of a standard barrel wall thickness gauge that was also set to 9 inches, this 9 inch distance from the breech is where the guns bore is measured also the wall thickness and to be sure measure the barrel thickness 9 inches from the muzzle. So if the .740 inch went into to the bore 9 inches though I have had it go in the bore to the handle the gun was out of proof though all was not lost if the barrel wall thickness was over thirty thousands of an inch there was a good chance of re proof but only if there was enough thickness at 9 inches from the muzzle say twenty five thousands. Though you did have to use your judgment of how much metal would be left after all the pitting if any was removed, so the gun did have to be a top maker in good condition to take a risk. The other rod for the wall thickness gauge was for .410 though hardly ever used the two Tdi's one Metric and the other Imperial. Though now all this is now done for you because last time I went to a sales show there where Gauges on every sellers table
The only lessons in my life I truly did learn from where the ones I paid for!
dam, your go, no go gauge idea makes sense, if dealing with uk made guns only...over here we have guns made all over the world, with many different standards...do you have a standard for minimum wall thickness in front of chambers?
What is the point of the go/nogo gauge when you have a wall thickness gauge at your disposal? I have no use for the go/nogo gauges when I have a bore thickness gauge at my disposal. By the way UK proof is of no use to anyone buying a gun outside of the UK.
dam, your go, no go gauge idea makes sense, if dealing with uk made guns only...over here we have guns made all over the world, with many different standards...do you have a standard for minimum wall thickness in front of chambers?
ed, why would you persist in the notion (we’ve been over this before) that there exists a magical, minimum, standard bore measurement that would be correct for all guns, old, new, of different gauge, and built in different countries of different qualities of steel?
Why do you persist in hounding people, seeking this magic number? This is not the first time you have attempted to wrangle a simple answer to this complex question. The answer is the same as the last time you asked.
Best, Ted
PS UK proof is of use to anyone buying a gun in signature countries of the proof law, most of Europe. Further, it is of use to people here, in the US, for knowing the bore dimensions of a gun, what the service level of use the gun was designed for, and whether those bore dimensions have changed, since the time of proof.
I searched but could not find Dr. Gaddy's wall thickness recommendations, but most of the Forums have changed formats/host since he was posting, and old threads have been lost. The PGCA search function ends at 2014.
From Brian Dudley https://parkerguns.org/forums/showthread.php?t=14438 I like to see numbers of at least around .025" minimum in the from half. Around .050" to .060" at the forend loop, and I find that most sound barrels run .090" to .100" in front of the forcing cones. These numbers are just ranges that I have found from measuring and firing different barrel sets.
Note to Dave Weber... continuation of previous post that was submitted prematurely...
As I was saying Preacher, Sherman Bell and Buck Hamlin took precautions to shield themselves from danger when firing their Damascus test guns. How can you be certain that a simple barrel guard is enough protection for other shooters in your vicinity? And why would you post wall thickness numbers that are considered minimum by Dudley and others, yet disregard those recommendations yourself? Who should we believe? Inconsistent data like that isn't going to help Ed or anyone else, is it?
A true sign of mental illness is any gun owner who would vote for an Anti-Gunner like Joe Biden.
The gun in question with the spring steel and leather handguard in place
"I personally measured the wall thickness of a 1906 L.C. Smith 16g No. 0E with “Good Two Rod” Damascus at .016”, 14” from the breech which [prior to having the wall thickness measured] had survived 250 2 1/2” 7/8 oz. Polywad Spred-R shells, 100 2 1/2” 7/8 oz. at 1145 fps. (about 8000 psi) loads [William Larkin Moore's], and 2 cases (500 shells) of 2 1/2” RST 3/4 oz. at 1100 fps (4,600 psi per RST) without rupture or dimensional changes."
My 3/4 oz handloads are listed in the manual at 5400 psi, a buddy chronographed the load at 1185 fps, and cases of that load have been through the gun.
The end-of-chamber MWT is .114" R (the thin barrel) and .118" L. 9" from breech is .032" R and .044" L.
It is my opinion that barrels that are thin from 12" from the breech to the muzzle (where pressures are much lower) are likely to split; not disintegrate
But the hand guard provides some additional safety.
Could you please share the wall thickness gauge that you use, and the end-of-chamber and 9" MWTs of your Lefevers? Thank you. Drew Hause
BTW while digging out the evaluation, I found these end-of-chamber wall thickness numbers: 20g No. 00 Armor steel Smith .088" L and .090" R 16g No. 00 Armor steel Smith .096 L and .105 R 16g No. 0 damascus Smith .108" L and .102" R 12g No. 4 chain damascus Smith .110" L & .103" R
So, all of you who own mechanical wall thickness testing devices disagree with Dewey V. ?, who says:
Mechanical Wall Thickness Gauges Are Worthless
Traditional barrel wall thickness gauges are inherently inaccurate due to the flexibility of the barrel arbors. This includes the vaunted "English Gunmaker's Style" that uses three rods mounted in a baseplate. The reason is that the arbors are solid rods that can be 14 to 18 inches in length and no matter how stiff you might think they are, they absolutely are not. They will flex measurably at the slightest provocation. This tool serves little more purpose than to impress the ignorant onlooker. It is guesswork with a dial indicator, nothing more, and was never the best tool for the job, even though it was the best that could be hoped for at a certain time. Thankfully, that time is passed. The ONLY widely available method of absolutely accurate wall thickness measurement is through the use of ultrasonic measurement. The tool that I use is the DeFelsko UTG P1 which is capable of measurement down to .008" in steel with an accuracy of .0004" (four TEN thousandths of an inch). Yes, it's expensive because actual accuracy costs, but it's worth every penny.
Here is some proof of the flexibility of the "traditional" gauge construction. The following video shows just how much movement there is in a .625" diameter water-hardening steel rod, at 16 inches unsupported length, chucked in a 5C collet in the lathe. This setup is much more rigid than any baseplate mount. The amount of deflection (a lot) versus the force applied (very little) should illustrate why ten different people will get ten different readings of the same barrel.
"But it's used in a vertical position" you say. Think about the fact that half of the barrel length is above the uppermost end of the arbor and that the inner wall of the barrel being measured MUST contact the arbor. Do you really believe that you can hold the inner wall in contact with the arbor, while not inducing ANY side load and causing it to deflect at all?
"But it's better than nothing" you say. No, erroneous information is worth exactly nothing.
"But so-and-so uses it and always has" you say. Of course, it looks snazzy, it impresses those that don't know any better and it's cheap to make. As you'd expect, it is also monumentally overpriced to buy, which further cements its "credibility" with the purchaser.
Apparently, he has so much credibility on this board when he speaks of other doublegun related topics, why not this?
Dewey is entitled to his opinion. He’s a very talented, extremely skilled individual, there’s no denying that. His opinions and views carry a lot of weight with people involved in our hobby, especially with individuals who are also interested and participate in the mechanical side of the hobby. I’m too am entitled to my own opinion, an opinion that has been formed from years of my own personal experience in addition to watching, and LISTENING, to many other, equally talented, sometimes vastly more experienced gunmakers than Dewey, especially ones that have a “speciality like barrel making, stocking, etc. I take it all into consideration, pick up on the things that make sense to me, ask a lot of questions, do a lot of thinking, contemplating and then form my very own, personalized opinion on the subject.
I emphatically disagree with his assessment on the use of mechanical gauges in regards to measuring wall thicknesses on barrels. In fact, I think it’s total bullshit. I’ve seen some of the very best in the business use mechanical gauges to great effect. And some of the finest guns in the world made today are still being made with the use of mechanical gauges just like the one I pictured earlier. There, that’s my opinion on it.😂. Does that mean that I also disagree with his opinions on spring making, metal working, bad vs good gun designs, etc. Hell no. I agree with a lot of what Dewey has to say on a myriad of gun related subjects. I still wish he posted here and shared more of his experience and knowledge, but I fully understand why he boosted out of this place too.
So, all of you who own mechanical wall thickness testing devices disagree with Dewey V. ?, who says:
Mechanical Wall Thickness Gauges Are Worthless
Traditional barrel wall thickness gauges are inherently inaccurate due to the flexibility of the barrel arbors. This includes the vaunted "English Gunmaker's Style" that uses three rods mounted in a baseplate. The reason is that the arbors are solid rods that can be 14 to 18 inches in length and no matter how stiff you might think they are, they absolutely are not. They will flex measurably at the slightest provocation. This tool serves little more purpose than to impress the ignorant onlooker. It is guesswork with a dial indicator, nothing more, and was never the best tool for the job, even though it was the best that could be hoped for at a certain time. Thankfully, that time is passed. The ONLY widely available method of absolutely accurate wall thickness measurement is through the use of ultrasonic measurement. The tool that I use is the DeFelsko UTG P1 which is capable of measurement down to .008" in steel with an accuracy of .0004" (four TEN thousandths of an inch). Yes, it's expensive because actual accuracy costs, but it's worth every penny.
Here is some proof of the flexibility of the "traditional" gauge construction. The following video shows just how much movement there is in a .625" diameter water-hardening steel rod, at 16 inches unsupported length, chucked in a 5C collet in the lathe. This setup is much more rigid than any baseplate mount. The amount of deflection (a lot) versus the force applied (very little) should illustrate why ten different people will get ten different readings of the same barrel.
"But it's used in a vertical position" you say. Think about the fact that half of the barrel length is above the uppermost end of the arbor and that the inner wall of the barrel being measured MUST contact the arbor. Do you really believe that you can hold the inner wall in contact with the arbor, while not inducing ANY side load and causing it to deflect at all?
"But it's better than nothing" you say. No, erroneous information is worth exactly nothing.
"But so-and-so uses it and always has" you say. Of course, it looks snazzy, it impresses those that don't know any better and it's cheap to make. As you'd expect, it is also monumentally overpriced to buy, which further cements its "credibility" with the purchaser.
Apparently, he has so much credibility on this board when he speaks of other doublegun related topics, why not this?
All measurements are erroneous. Every single one. So, trying to pare through the hyperbole to get meat of the matter, how does Dewey respond to those that claim to be able to repeatedly measure known thicknesses with satisfactory accuracy and precision? I build decks and barns with tape measures, though they are not nearly as precise or accurate as vernier scales and micrometers. The deck hasn't fallen down yet.
This seems like "my dog's better than your dog" sort of BS. Par for the course on doublegun.com, however.
I didn't know about ultrasonic until lately. So I can't speak to it's accuracy. In a Double gun class I took 3 separate mechanical gauges with 3 people using them came within .001 of each other in measurement so it was repeatable. Does anyone have an idea what an ultrasonic device costs?
I didn't know about ultrasonic until lately. So I can't speak to it's accuracy. In a Double gun class I took 3 separate mechanical gauges with 3 people using them came within .001 of each other in measurement so it was repeatable. Does anyone have an idea what an ultrasonic device costs?
Could you please share the wall thickness gauge that you use, and the end-of-chamber and 9" MWTs of your Lefevers? Thank you. Drew Hause
Preacher, the wall thickness of my Lefever barrels, and the means I use to evaluate them is 100% irrelevant here. I think your silly and unreasonable request is little more than an attempt to deflect from my legitimate question. My comment and question concerned why you would posts links to recommendations concerning safe barrel wall thickness from others such as Dr. Gaddy, Jay Shachter, and Dudley, yet totally disregard those numbers when using your one-and-only Damascus barreled shotgun, an OE Grade L.C. Smith
We have had many discussions on barrel wall thickness here over the years. You know as well as I do that virtually nobody here would consider the .016" minimum wall thickness of your gun adequate, especially at 14" from the breech. If someone here asked whether it would be wise to buy a gun with .016" MWT at that point, the general consensus would be to avoid it like the China Virus.
.016" is about the thickness of a paper matchbook cover. That's why matchbook covers were commonly used to set ignition points gaps in the past, when feeler gauges weren't handy.
You mention the number of various loads that were fired in your 0ne-and-only Damascus barreled gun, prior to measuring them. Yet you say there was no dimensional change from firing all those shells. How can you know that to be true, if prior measuring had not been done???
What is even a bigger concern is whether or not your own measurements are accurate. I say this because I vividly recall how you argued for three days that lengthening the chambers of vintage American doubles would result in an INCREASE in wall thickness at the end of the re-cut chambers. Miller and I had to provide pictures and detailed explanations to finally get it through your skull that removing metal in that region would not, and could not, INCREASE wall thickness. I'm not sure we ever really convinced you. As you yourself have frequently stated, barrel evaluations should be done only by those who have the proper measuring equipment, AND the EXPERTISE to use it. You cannot simply Google your way to becoming an expert. It takes a combination of facts, skill, experience, and intelligence.
You also frequently admonish and lecture guys about a lack of "personal responsibility" when they persist with using guns that you deem unsafe without ever having examined them. Here is an example from the document you provided the link to:
"The following is a recommendation for evaluations that should be undertaken prior to using ANY vintage barrel; Pattern Welded, Decarbonized, or Fluid Steel. The shooter may choose to do more, or less, based on his (possibly misplaced) confidence in the safety of the barrels and tolerance of uncertainty. Choosing to make no effort to determine barrel integrity is foolish in the extreme. The man pulling the trigger is ultimately responsible for subsequent events. If we only shoot/hunt alone, we can choose to use whatever shotgun and load we wish (if legal). But most of us shoot clay targets with others, and hunt with a friend, son, grandson or granddaughter. We must ask ourselves what will be our explanation should a piece of shrapnel from our gun pierce the skull of a friend or child, leaving them paralyzed, mute, and bedridden for the rest of their not-much-of-a life? And what is our plan to pay for the lost wages, pain & suffering, and life-time care? If we choose to use a Damascus barrel “proven to be intrinsically dangerous” we WILL lose the personal injury lawsuit if no effort was made to evaluate that barrel. And there is no doubt that a host of “experts” would willingly testify in the civil trial as to our irresponsibility."
Now, when you talk about the potential of losing a personal injury lawsuit as a result of a barrel rupture injury, how do you think you would fare if your one-and-only Damascus barreled gun caused an injury, and it could be shown in court that you knew the barrels were dangerously thin, according to your own admissions, and data you provided from other experts in the field? Do you think that your uninformed and unproven opinion that a leather covered barrel guard was enough to protect those innocent women and children around you from being maimed, paralyzed, mute, and bedridden? Could you prove the pressure of the load that was used at the time when the gun barrel ruptured? And look at your post #58 for MWT's from that Parker Forum thread where you posted that the minimum at 16" from the breech is .022" for Standard STEEL barrels, while yours is .016" at 14" from the breech. Your friend Homeless jOe would advise you to donate your one-and-only Damascus barreled gun to a Cracker Barrel to hang on the wall.
But that would leave our self-styled shotgun barrel "expert" with zero Damascus barreled guns. That's the great thing about the internet... anyone can pretend to be something they aren't, and some people will be fooled. I found this quote at the end of your barrel evaluation essay:
Mark Twain “It ain’t what you don’t know that gets you into trouble. It’s what you know for sure that just ain’t so.”
A true sign of mental illness is any gun owner who would vote for an Anti-Gunner like Joe Biden.
Wall thickness recommendations can reliably be made based on the measurement a large sample of unmolested barrels; for my purpose vintage pattern welded and fluid steel. That data has been posted.
Recommendations for vintage shotguns are however dependent on: The tensile strength of the steel used to fabricate the barrel The presence of pits as determined by visualization with a bore scope or camera. Mechanical gauges are unable to measure the thickness at the bottom of pits; I would be very interested if the current ultrasonic devices can do so. The pressure of the load the shooter intends to use
SO examiners must individualize their advice. Simple minds want simple answers ed but it's not that easy.
Edd,the information is out there on the interwebb but you have to do some work if you are unsure about a guns safety don't sell it.if you don't have the ability to evaluate the condition of a gun don't buy or sell.
Edd,the information is out there on the interwebb but you have to do some work if you are unsure about a guns safety don't sell it.if you don't have the ability to evaluate the condition of a gun don't buy or sell.
As I've said before, even recently, working to find out the answers for himself is against Ed's religion, or lack of work ethic, whichever applies. This has been his modus operandi for as long as he has been a participant. He cannot be coached, or even embarrassed, into changing his "style". I actually believe he gets some weird sort of enjoyment from being chastised.
stan,an udders... have you posted your barrel safety guidelines some wheres on the net? if so, pls provide link for us all to see..otherwise, pls esplain how we can git in yo head an find the info you refuse to reveal here...
I have a single shot gun that has a good barrel wall thickness: between 1.5 and 2 mm. It was made before 1888 (Wiggan&Elliott closed), and a great gunsmith told me that it can endure up 1.300kg/cm².
The barrel rings like a bell.
What do you think?
28 ga, hammerguns and all shotguns and rifles made by hands. Waidmannsheil 🌿📯
Hermano campero. I have a bit of 'campero' PTSD Pollo Campero is sorta the Kentucky Fried Chicken of Guatemala, and on one of our mission trips 2 of the team members went with brother Gideons to the next town and had lunch at Campero. They returned with Norovirus and the whole team got sick! The inside bathroom was continually occupied and folks were running to the outhouse and the family dogs thought it was great fun to chase and watch the Gringos
The answer to your question illustrates why the answer is rarely simple.
The best answer is "To what service and proof pressures was the barrel proved?" 1300 kg/cm² is about 18,500 psi CIP 12g “High performance/Superior Proof” is 1320 BAR = 19,145 psi for a Maximum Average (Service) Pressure 1050 BAR = 15,229 psi Contrary to the mythology, U.S. makers of vintage doubles DID prove their guns (using pattern welded and fluid steel tubes that had been proved in Belgium) at 16,000 - 18,000 psi
If your gunsmith calculated that pressure based on a bursting or hoop stress formula, which don't work well for unobstructed shotgun barrels, he needed to know the steel tensile strength. Is the barrel pattern welded or fluid steel? Siemens, Cockerill or Krupp?
1.5 - 2 mm = about .06 - .079" I assume that is the minimum wall thickness and certainly not the end-of-chamber, which we also need to know (and the 9" from the breech would be helpful also)
The gun is a 12g? What does the bore measure and is there evidence of honing or other barrel modification?
Bell ringing MAY indicate the rib is tight, but little else.
I call myself a campero because I love the countryside, hunting and nature 😅😅 no chicken 😅😅.
I wrote on this forum about this gun. It is a 28 ga Wiggan & Elliott. It has a 28 ga chamber but a 30" 24 bore barrel: overvored! You can see pictures if you look for.
Don't know what steel, but it rings like a bell.
I test fired my Wiggan and my B525. It was amazing. Faster shooting with the old single barrel than with the new over-and-under, but this is other post (sorry).
Best regards!
28 ga, hammerguns and all shotguns and rifles made by hands. Waidmannsheil 🌿📯
any opinions you obtain here about your guns will not be as valueable as that of your gunsmith, who has actually seen your guns and has given you his expert opinion...
I'm sorry, Ed, but I have no information about that. The gunsmith told me that my shotgun has wide barrel wall and the oversized to 24 bore (overvored). In the barrel table there's .579: 24 bore, not 28. That surprise me, so I'm looking for info to resolve it, but there is poorly info about Wiggan & Elliott makers.
Here you can see the Wiggan overbored barrel next to a normal SxS 28 ga.
So hope you can help me.
28 ga, hammerguns and all shotguns and rifles made by hands. Waidmannsheil 🌿📯
Ed you mentioned your standard is .090/.030 what methods are you currently using to assure that the guns you are buying or selling meet this criteria? If someone else is providing this information for you, what are they using?
well, numbers are meaningless, unless one can relate them to some scale of value...
like the number 12...by itself, hit don mean much...but when you apply it as 12 inches, and call it a foot, den it takes on ah whole lotta meaning...
same thing wid barrel wall measurements...alone, they mean little...but once applied to a standard of guidelines, then they become something of value, when applied to evaluating the safe shooting qualities of shotgun barrels...
Yes of course flapper zapper,he could always say .110 .040 and that will make you happy because it most certainly is a number two numbers to be exact if you don't like that number have him say a number you like and if you still don't have a positive affirmation and interest in those numbers don't buy it
All this palaver would be unnecessary if we had proof laws in this country, like the Brits. Either the gun is safe, or it isn’t. Can you imagine the boondoggle that would be?
I suspect the same apprehension regarding letting the government decide what guns were "good" was present then, as now. And the U.S. makers were proving their guns in-house
I don't know anyone who has elected to prove their barrels, and don't know the cost thereof. Should proof testing be required by government edict, the cost would of course be passed on to the consumer.
drew, thanks for your continued efforts to educate us re doublegun history and other topics...
as for the need for a gubmint proof house here...as has been proven over the last couple of centuries, we do not need such a service here...
for the most part, doubleguns made here are made safe...with an extra amount of wood and metal to make them incredibly durable...
a real credit to our doublegun makers...
for example, packers an stevens brand guns are mostly clunky an ill balanced...however, they are among the most durable of all doubleguns made here or anywhere...
All this palaver would be unnecessary if we had proof laws in this country, like the Brits. Either the gun is safe, or it isn’t. Can you imagine the boondoggle that would be?
It seems to me that the Brits are a bit more accepting of government telling them what they can and cannot do than are we Americans. There are centuries of evidence to that.
Do you happen to recall why America came to be, in the first place? It can be spelled out easily, F-R-E-E-D-O-M ............ from excessive and burdensome laws and regulations.
All this palaver would be unnecessary if we had proof laws in this country, like the Brits. Either the gun is safe, or it isn’t. Can you imagine the boondoggle that would be?
It seems to me that the Brits are a bit more accepting of government telling them what they can and cannot do than are we Americans. There are centuries of evidence to that.
Do you happen to recall why America came to be, in the first place? It can be spelled out easily, F-R-E-E-D-O-M ............ from excessive and burdensome laws and regulations.
That’s a bit of a stretch Stan. It has nothing to do with personal freedoms, it has to do with safety. And at the time the proof laws were developed the best way to determine whether a gun was safe, for either a Redcoat or private citizen, was to shoot the gun with an overload. Product liability was a thing in the 17th century and it still is today. Ed
No eeb, personal responsibility and due dillgence American company's proofed there guns and over built them what happened in the intervening years to the gun isn't the mfg.problem it's the buyers ,buyer beware have your new purchase checked by a professional.
You misunderstand my comment. I agree with doing your due diligence and caveat emptor, etc. Whether you’re buying a shotgun or a used car, have it checked out by someone who knows what they’re doing if you don’t have that expertise. British proof laws give the buyer in the UK some assurance that what is being bought at auction, for instance, has an acceptable degree of safety. An industry association might be able to do it here, but I wouldn’t trust any governmental agency to do it; Uncle Sam has trouble delivering the mail.
Ed you replied to my post.”why for do you ax.” I believe you meant to write the word ask. I ask because you are a licensed Gun dealer and publicly stated your standard of .090/.030. You have not mentioned the equipment or the method used for taking these measurements to assure not only the guns you buy are safe. More importantly whether it is it safe to assume that all the shotguns you sell have bores that meet your personal minimum safety standard? Many of the members have shared the tools and methods they use. I think it’s a fair question, what do you use?
So edd you buy a gun take it to a gunsmith it's not .030 .090 so you destroy it ? Sell it to an unsuspecting customer ? I'm curious how you know the status and safety of a gun with out checking it your self 30 years as a gun selling business you should have be able to buy the minimum equipment to keep your customers safe.what numbers do you consider not safe and not safe to pass on to a customer.
Well edd that says it all all the great information given to you free and this is how you apply this information ,why in the world did you keep asking for technical information and standards for judging shotgun safety when you have no intention of using it .let the buyer beware is the ultimate resonsability of anyone dealing with you
William back on p. 8 "the wall thickness of my Lefever barrels, and the means I use to evaluate them is 100% irrelevant here." And the request to do so is "silly and unreasonable"
The title of this thread is "Wall thickness measurement" and I and others have provided a substantial collection of numbers to help establish the standards of the makers. Either you do not have a wall thickness gauge Or you have numbers, which could benefit the forum members, but which you choose not to share.
Look in the mirror as you say the above to yourself.
You remind me of a guy that used to pretend to be blind and sat on Broad Street In Augusta, GA about 1960. He wore dark eyeshades and dressed like a homeless guy, and held out a tin cup, begging for donations. At the end of the day he would look around and, when no one was looking, he would get up and walk away with no cane, obviously with good eyesight.
Don't try to spin this post as a "personal attack". It is a simple observation.
I'm not beyond whining (begging) in the interest of science gentlemen and would very much like more small gauge end-of-chamber MWT numbers
The ONLY 28g barrel that I've measured was a Phil's Parker checked at Mike's cow pasture shoot in 2020. I did not keep the documentation but as I recall, both end-of-chambers measured about .105"
The earliest 28g pressure I've found were published in Frederick Toms, Sporting Guns and Gunpowder, 1897 with 3/4 oz. and + 10-14% 28 gr. Bulk (2 Dram) – 2.81 tons = 8,322 psi 18 gr. Dense (2 1/2 Dr.Eq.) – 3.01 tons = 8,994 psi
DuPont Brandywine Experimental Station data cited by Charles Askins in 1933, with DuPont Bulk Smokeless Powder 28g 2 Dram 5/8 oz. - 4.66 X 2240 = 10,438 psi + 10 - 14%
Since 28g pressures run higher than larger gauges, it would make sense that the end-of-chamber MWT would be slightly greater.
And a gloriousIndependence Dayto each of you and your family
Drew Hause, very interesting your reply. It's the first time I read that 28 ga have more pressure than other gauges and that's the reason barrels thickness are wider than 20, 16, 12... I don't think so, but this is new for me and I'm in doubt.
You have information of the earliest 28g pressure testing. I suposse with black powder, so current pressure must be higher.
This is an interesting thread! Thanks!
Regards!
28 ga, hammerguns and all shotguns and rifles made by hands. Waidmannsheil 🌿📯
Hermano Campero: a helpful chart from “Proof Tests and Proof Marks: Practices of Manufacturers in the United States”, 1934. Limits are based on the 1925 British Rules of Proof. Long tons are converted to PSI simply by X 2240, and the numbers were measured by LUP so require adding 10 - 14% for modern piezo transducer numbers. It is important to note that the standard 28g load then was 5/8 oz. and 2 1/2" .410 only 3/8 oz. The 2" .410 was 3/10 oz.
Modern U.S. SAMMI standards for 28g and 2 1/2" .410 allow max. pressure of 12,500 psi; 3" .410 13,500 psi. 12g and 16g are 11,500 psi and 20g 12,000 psi
but slightly LESS end-of-chamber wall thickness for small gauges, but the Category 1 “Standard Steel” is Non-alloy AISI 1045 with tensile strength = 101,526-123,137 psi Category 2 is Non-alloy AISI 1060 and 3 Alloy with 3% Chromium and 2% Molybdenum with a Tensile Strength of 116,030 - 159,396 psi
I checked a icd 28ga.its .105 at the end of the chamber I have another icd 28 but the barrels are much heavier and it is .130 at the end of the chamber
Preacher, I did reply to your last nonsensical request about five days ago.
It appears that Dave feels you are too sensitive to handle the truth concerning the very conflicting data you have presented concerning safe barrel wall thicknesses according to guys considered to be knowledgeable about shotguns, and the thin honed out barrels of your one-and-only Damascus barreled gun.
I guess censorship is helping you. But it isn't doing a damn thing to help make this forum a source of factual knowledge.
A true sign of mental illness is any gun owner who would vote for an Anti-Gunner like Joe Biden.
Sensitive enough William to respond in detail to your question back on p. 7 regarding my ratty Smith OE, and sharing my rationale for using the gun, knowing that my decision would be criticized.
You however dismiss a reasonable request to share your Lefever wall thickness numbers, on a thread about measuring wall thickness, as nonsense. Why not man up and just admit you don't have a wall thickness gauge?
I recently read a review article regarding narcissistic personality disorder. There are several variants. Those with one variant derive some perverse pleasure in manipulating and aggravating others - it feeds into their sense of omnipotence. And the fall back when confronted is to play the victim. That would be ed. The most toxic variant is when the individual's greatest need/desire is for others to fear them - it feeds into their sense of invincibility. They respond to confrontation with rage and revenge, and often violence. This variant destroys every relationship, esp. in families. No one here fears you William.
Take a break William. Find some healing. Lose the hatred. If not for yourself, for your family. Restoration of broken relationships may still be possible.
I was hoping this could be a reference thread for future questions regarding wall thickness, but it typically went south. Dave can do with it what he wants.
When measuring the wall thickness, is there a standard for how many measurements are made around the circumference of the barrel at each depth? I.e. do you measure at 12, 3, and 6 o'clock at each location? Or some other interval?
Woodreaux: back on p.4 I posted an image of my set-up. Having the barrels secured with bungee cords affixed to a weighted box allows me to rotate the barrel while I'm measuring. Typically the thinnest spot is the lateral wall. On the report I provide I document only the MWT at the points shown, but will note other numbers (or the location of significant pits seen with the bore scope) under "Comments" if needed. "Chamber" is chamber length and diameter. The breech end of chambers of c. 1900 12g U.S. doubles is usually .809” -.812”, tapering to .795” - .798”, and unfortunately I've measured some chambers that were honed to remove pits also.
ed will note I have my pattern welded barrel MWT recommendations on the form. Obviously those recommendations can be discussed with the gun owner and modified depending on the barrel composition, based on incomplete but IMHO pretty good data ie. we now have composition analysis and tensile strength testing on a significant sample of vintage barrels: Twist and Crolle Damascus tensile strength is about 55,000 psi Winchester Standard Ordnance and other "cold rolled" Bessemer/Decarbonized steels and AISI 1020 are similar in strength at about 60,000 psi c. 1900 Belgian sourced “Fluid Steel” used by all the U.S. makers (Cockerill, Siemens-Martin & Krupp Open Hearth) and AISI 1030 are similar in strength at 75,000 - 85,000 psi Krupp Fluss Stahl (Homogeneous Fluid Steel) was introduced about 1890 might be a little stronger AISI 1040 (and modified), Vickers, Cockerill Acier Universel or Acier Special & Bohler “Blitz” are similar in strength at about 100,000 psi Winchester Nickel Steel, Marlin “Special Smokeless Steel”, Remington Ordnance Steel, Krupp “Nirosta” (1912 patent NIchtROstender STAhl 21% Chromium / 7% Nickel Stainless Steel introduced in 1913), 4140 Chrome Moly (not used until after 1930s) and 4340 (Chromium, Nickel and Molybdenum) are all similar in strength at > 115,000 psi
doc drew, this is all very nice, but after one inspects the barrels and takes measurements at various points, then what?...
based upon measurements only, what are your guide lines to determine if gun is safe to shoot?...
so far, no one else here seems to be able or willing to answer that question...it does not have to be complex...
unless no one here has enough experience measuring barrel walls to make judgements re suspect barrels...
and you will be happy to know that this is the last time i will ax this question in this thread...
i give up...
Answer your own questions. What are your guidelines and how do you determine that they are met? You've been asked directly and refused to answer multiple times. Why can you not do this?
Ed, I bought a gun from you. Afterwards I had it inspected and found it had been honed considerably and was out of proof. Still safe to shoot but you never mentioned a word about that in your ad. And that gun, you knew, was meant to be used by my daughter-in-law. I'm still ok with the purchase. But you are the last person on this board to be talking about safe guns. Sorry Ed, you're a very smooth talker but you have zero credibility.
Check proof check mwt check bore diamiter,you have all this information for free given to you use it EDD.argo you are way to nice to EDD you should have returned the gun . so now it's on you and you accepted it and let him off the hook.
...argo you are way to nice to EDD you should have returned the gun . so now it's on you and you accepted it and let him off the hook.
Actually, it's much better for Argo44 this way. If he had simply returned the gun, and got his money back, he wouldn't be able to whine and complain about it here, for the rest of his life.
What you will never see in all of this repeated complaining about ed and this shotgun, is an admission from Argo that he failed to request bore measurements before he purchased the gun. We have no Proof Laws here. And the vast majority of gun sellers do not have the equipment to measure bores or wall thickness.
I neglected to ask for bore dimensions of a gun that was advertised pn Gunbroker as a 12 gauge H grade Lefever. It turned out to be the only known H grade Lefever that is a 10 gauge. I did not complain, nor did I ask for a refund.
A true sign of mental illness is any gun owner who would vote for an Anti-Gunner like Joe Biden.
Well, even if Argo had requested bore & wall thickness measurements, he wouldn’t have gotten them. Ed’s already admitted that he doesn’t own the tooling or even know how to take these measurements. That in itself is extremely suspect when it comes to guy who’s been peddling guns for a long time…..if your selling quite a few vintage guns as a job or even a hobby, invest in the tooling to give those very basic measurements. If he would’ve bought that tooling a few years ago, they would’ve already paid for themselves 10x over. The other part of this is if you did take a gun you bought from Ed to a guy for measurements and found that the barrels were suspect…..do you think you’d get your money back from him? He’s got quite the track record on his return policy. I doubt he even has a local gunsmith that does his measurements for him as he has never posted any type of measurements in any ad I’ve ever seen from him.
As tiresome as Argo can be be at times, you’re becoming equally as tiresome with your continuous sticking up for this attention seeking goof ball. Give it a rest. Ed brings all of this on himself. I’ve had a few friends over the years that would go to bars and start fights, and instigate drama. For no real reason other than to get excited, get a rise and have something to talk about on Monday. I used to help them get out of jams all the time especially if they picked the wrong fight….eventually I wised up and started letting them fend for themselves. They eventually gave up on the fight picking and instigating and settled down into somewhat normal adults. Ed brings the shade onto himself. He does it for attention. No need to try and come to the rescue for a dipshit like Ed for the sake of just trying to prove a point. Hopefully he’ll learn on his own one of these days, but I highly doubt it.
fusil, you are spewing from your mouth, lots of brown colored, foul smelling liquid that normally emits from the other end of a male bovine...
~never indicated that i do not possess bore wall thickness gauges...
-you have no clue what my return policy is...
~the word games i play here have nothing to do with my business policies, except to help me weed out malcontents before i make the mistake of shipping a gun to them...
and as no one here seems to have a clue as to what minimum bore thicknesses are, what the hell difference does it make anyhow?
argo: how long ago was hit dat we did dis deal? 10 mebbe 15 year ago...ah have furgot...
but anyways, this seems like the third or fourth time you have come on this fine forum, bitchin an moanin bout dis dam gon...
hits like every few years you go on the rag an drag this crap up...agin, an agin, an agin on an on infer nitum...
as i recall, old ed evaluated this gun and deemed it safe to shoot...therefore, i deemed it safe to shoot... hell, ah dont even remember if i saw any evidence of honing in the bores...
I read many pages since the last time I posted, but the mention of British proof caused me to wake up. British proof is ridiculous and useless. The Brits make thin wall guns at their factories and shade tree British gunsmiths grind them out to be even thinner. The Brits will pass a .008 gun as long as it doesn't blow up when testing it. It is a crazy, useless, government excuse to tax. US proof would be even worse, with a minimum wall thickness of .150 with a sliding scale to make it .180 by the year 2030.
as a matter of interest, my old friend, teacher and guru, ed lander, now deceased, spent at least one summer in england, learning the skills and practices of some of the gunsmiths working in the birmingham gun trade...it was the general practice of some firms, not to work on guns in for repair unless they met certain safety standards...as to barrel wall thicknesses, the standard was at least .090 thousands of an inch in front of the chambers and a minimum of .030 thousands, seven or so inches down from the muzzles, which is often the thinnest place in the barrels, before the choke tapers begin...
hence, the origin of my 90 30 guidelines for doublegon happiness...
Your out of your mind edd like eightbore said the English use proof as the deciding factor on gun safety ,not an absolute 30 90 wall thickness .dont sniff glue and tell stories
mc, you are sounding more and more like an angery rude child locked down in the basement with nothing to play with, but your ipad and yourself...sad, so sad for you...
an, it is my understanding that some children do sniff glue...dont do that...it is bad for your health...it destroys your brain cells...you will need all of those when you grow up and become an adult...
No more like a parent with a petulant child edd. you are doing 3xactly what you did with the dangerous high heat case color to justify your torching guns to add colors ,you state 30 90 like it means something without context
No more like a parent with a petulant child edd. you are doing 3xactly what you did with the dangerous high heat case color to justify your torching guns to add colors ,you state 30 90 like it means something without context
"you state 30 90 like it means something without context"
here is the context...
my old friend, teacher and guru, ed lander, now deceased, spent at least one summer in england, learning the skills and practices of some of the gunsmiths working in the birmingham gun trade...it was the general practice of some firms, not to work on guns in for repair unless they met certain safety standards...as to barrel wall thicknesses, the standard was at least .090 thousands of an inch in front of the chambers and a minimum of .030 thousands, seven or so inches down from the muzzles, which is often the thinnest place in the barrels, before the choke tapers begin...hence, the origin of my 90 30 guidelines for doublegon happiness...
I would rather see Fred Good use the British system, "Blow up or not blow up". I wonder how many of Fred Lander's colorful creations would survive British proof? How do we like the "Fred" name change to give Good and Lander some identity with Fred Sanford?
one that comes to mind is a 12 ga parker gh with ratty damascus barrels...
in a fit of entre pre murial risk taking, i asked old ed to sleeve the barrels for me...wanting see how it turned out and if there was a cost vs revenue advantage with having guns sleeved and then sold for humble profit...
ed said, well it costs from one to three thousand, including the blanks...so i axed, what does one git fur a thousand bucks?
his response, a safe, regulated gun with fluid steel barrels...ok, says i, lets do it...
old ed sleeved the barrels, with seams showing...to be safe, he proofed the barrels with winchester proof loads...as promised the gun shot both barrels to point of aim at 30 yards...the finish work could have been better, but thats what i got for a thousand dollars...anyway, the fellow I sold the gun too won his state skeet shooting championship with that old sleeved parker...
thats the story...and as it turned out, l lost money on the deal... so that was the first and last sleeving job old ed ever did for me...
How did ed remotely proof the barrels ,does winchester sell proof loads and what gun are the proof loads ment for a field gun? Duck gun 3inch mag gun are are guns created equal .are the winchester proof loads equal to Parker proof loads what criteria was used to analyze the gun for damage or was it. "hey it didn't blow up"
As far as “minimum wall thickness” that I’m comfortable with, it depends on the gun and what cartridges I plan on shooting through it, but I am ok with spots down as low as .018 at the 9” from breech mark. Obviously over .020” is preferred. This assumes suitably thick and unaltered chambers and barrels in otherwise good condition.
Last edited by TCN; 10/19/2210:54 AM.
"More important, we hoped that when Autumn came, the birds would fly"
TCN, I hope your figures are transposed from Muzzle to Breech. --018" from the breech would be dangerously thin and a real risk of injury to the shooter/bystander. I would be skeptical of anything less than .040" in a light game gun and prefer to see.045" at a point 9" from breech.
Since this thread is about barrel measurements and their relation to safety, would someone explain how the bore diameter measurements come into play?
The reason for my question: I've got an 1890s EM Reilly 16g with Damascus barrels made by WJ Jeffery sometime between 1927 and 1955 judging by the address (9 Golden Square). I measured the internal diameters and both barrels are smaller than the 0.663 spec of a 16g. The right barrel measures .657 throughout the length. The left barrel measures .658 except for a short section about 3" back from the muzzle where it measures .662. The diameter at the muzzle is back to .658.
I don't know what to make of the section that is .004 wider than the rest of the barrel. I would appreciate any input / education.
There are no set rules about bore diameters, only that they shall be measured and stamped. That said I have seen 12's with tight bores and what we think of as over bores all being original. As to your left barrel it sounds like some removed a bit of metal to try to get some choke effect in a cylinder gun.
It can have meaning when you check the diameter to the proof if the difference is great it could mean thin walls or if a type of gun was traditionally 729 bores and it's now 740 might indicate wall thickness problems.so bore diameter might be important
Most of the light game guns, and most vintage doubles, from various internet dealers I observe have wall thickness no where near .040, with most advertised as under .030. Many are under .025 with reproofed 2.75” chambers. No thank you.
Most light game guns were made with thin tubes, .025" or less when new. You really need to look at the original bore diameter and barrel wall to understand what you have and how safe it is. I have no issues with a gun that is thin out towards the muzzles as long as it has plenty of wall thickness in the first 9" or so and it's price reflects the barrel condition.
And never buy a gun from someone who won't let you have time or shipped to a double gunsmith who has the tools and knowledge to do a proper evaluation or avoid the hassel and go to a gun dealer with tools and knowledge and stands behind his product .there is much more to a proper gun evaluation then 30 90 ?
Because you are worried about denting/repairing or because you think there’s a potential for a random burst at that thickness?
My first concern with vintage guns is safety. I’m with SKB on this in regards to location of the thin spot of the barrel. If it’s .025 towards the muzzle, no problem. If it’s .025” at the end of the forend where my hand is, no go. More dealers are disclosing the MBT, but they don’t say where on the barrel the thin spot is. That’s what you ask when you call them up. These tolerances are simply my personal policy, YMMV.
Thanks for all the info. My question came largely from thinking about Damascus's go / no-go bore gauge. I was thinking about how that would affect the decision about a guns safety.
What I'm understanding is that if a gun is well out of proof, there's reason to suspect the walls might be overly thin. A gun being in proof is no gaurantee of good wall thickness but is a better bet.
Here's what I found on my Reilly, using a Manson wall thickness gauge and a skeets bore gauge:
Right: 0.655" diameter and 0.068" wall thickness @ 9" from breech. MWT 0.048" @ 9" from muzzle
Left: 0.657" diameter and 0.070" wall thickness @ 9" from the breech. WT 0.048 @ 9" from the muzzle and MWT 0.044 @ 6" from muzzle.
From the flats, I see the gun was proofed at 17/1 bore, which is 0.655". So the gun is well within proof (suggesting it hasn't been excessively honed, etc) and has plenty of wall thickness throughout to be safe to shoot.
Apropos of nothing and offered only as a funny anecdote, not to support a viewpoint . . . I was talking to an old engineer I used to shoot with about what I thought were some very thin barrels that he was shooting with. “Aren’t you worried?” I asked. He said he wasn’t and I persisted “why not?”
“For the same reason that the walls of my cartridges don’t burst, pressure takes the path of least resistance”.
"More important, we hoped that when Autumn came, the birds would fly"
Barlow's Formula P = 2 x S x t / D P=Bursting pressure in psi. S=Tensile strength of material in tube wall. t=Wall thickness in inches. D=Outside diameter in inches.
Burrard preferred the Alger Burst Formula Burst pressure = Ultimate tensile strength x 3(OD – ID) / OD + 2xID
Lame Formula Burst pressure psi = Ultimate Tensile strength x (OD squared – ID squared) / OD squared + ID squared
Mechanical engineers (plural) with whom I have discussed barrel bursts explained that all 3 apply to a pressure vessel; a pipe capped at both ends. An UNOBSTRUCTED shotgun barrel is very very briefly "obstructed" by the ejecta, which very quickly begins to move in response to the gas pressure, which then rapidly falls.
SO the bursting formula do not work well for non-obstructional shotgun barrel bursts
Anywhere along the length of the tube where the gas pressure exceeds the bursting pressure, the burst becomes the "path of least resistance."
An UNOBSTRUCTED shotgun barrel is very very briefly "obstructed" by the ejecta, which very quickly begins to move in response to the gas pressure, which then rapidly falls.
This is exactly why I have so much problem believing that an overloaded (double charged, wrong powder, etc) shell, will ever burst the barrel wall several inches down bore. The pressure on that curve is down to ~2000 psi at 7 inches from the breech. That's less pressure than my JD tractors' working hydraulic pressures, and they are contained in some very thin walled tubing and run for thousands of hours at those pressures, including pressure spikes.
Until proven wrong with empirical data I will always believe a down bore barrel burst is caused by an obstruction other than the payload itself.
I once asked Mike Orlen about pitting near the muzzle end of barrels being a potential burst area and his response: "a garden hose could handle the pressures near the barrel's end." Gil
The digital image is part of the Winchester Repeating Arms Company Collection but includes a notation “Hunter Arms Co”. WRAC was acquired by Western Cartridge Co. Dec. 22, 1931, so it is impossible to know if the curve was generated by Winchester, Western, Hunter Arms, or (very possibly) the Burnside Laboratory of the E.I. du Pont de Nemours & Co.
PROOF LOADS Loaded with FFFg black powder. Shot presumed to be No. 6. Pressures were measured by crushers (LUP - Lead Units Pressure) and modern piezoelectric transducer measurements would by 10 – 14% higher F - 10g 2 7/8” 9.5 Drams with 2.36 oz. shot = 16,000 psi A - 12g 3” 8.265 Drams with 2.187 oz. shot = 17,250 psi G - 12g 2 3/4” 7.53 Drams with 2 oz. shot = pressure not recorded B - 12g 2 3/4” 6.5 Drams with 1.687 oz. shot = 14,200 psi C - 16g 2 9/16” 6.5 Drams with 1.687 oz. shot = 13,750 psi It seems likely the ‘B’ 12g and ‘C’ 16g labels were switched D - 20g 2 3/4” 5.74 Drams with 1.5 oz. shot = 14,625 psi E - .410 2 1/2” 2.377 Drams with .624 oz. = 15,625 psi
MAXIMUM STANDARD LOADS 1” peak pressures H - 12g 3” ‘Record’ 1 3/8 oz. shot presumed 1275 – 1295 fps = 13,250 psi I - 12g 2 3/4” ‘Field’ 1 1/4 oz. shot presumed 1330 fps = 10,750 psi The label ‘J’ for 28 gr. Ballistite and ‘K’ for 3 1/2 Drams DuPont Bulk appear to have been switched on the pressure curve graph. Dense Ballistite clearly generated greater pressure than DuPont Bulk. K - 12g 2 3/4” 1 1/4 oz. 28 gr. Ballistite = 12,900 psi J - 12g 2 3/4” 1 1/4 oz. 3 1/2 Drams DuPont Bulk = 10,000 psi
The pressure curves essentially meet at 5” at 7000 psi; at 10.1” 2625 psi (DuPont Bulk) to 3000 psi; at 15.5” 2000 psi; at 22.1” 1500 psi
Well Stan put a pump on your tractor that doubles or triples the pressure I think double charge of incorrect powder will cause problem for a gun I have seen a fox blown up because of this exac problem to much pressure barrel gave it up
Unless the overcharge pressure doesn't drop enough and the wall thickness decreases enough to have a catastrophic failure. I never say never when s**t happens
.012"? Well sure. I should have qualified my belief by stating I was referring to something reasonable. What's reasonable? For one, what it left the manufacturer with.
Beyond that, what's reasonable for me may not be for you. I am only responsible for my decisions about this. There are limits to everything. I'd like to see that engineer if he were to be confronted with a chamberless, barrelless gun about to touch off a round. I don't think he'd be standing beside it. I wouldn't, obstruction or no.
I'm still not convinced that Perazzi had no bore obstruction. Show me proof it didnt. Why would that pressure blow through .012" high tensile steel alloy when it could exit down bore?
Unless the overcharge pressure doesn't drop enough and the wall thickness decreases enough to have a catastrophic failure. I never say never when s**t happens
Without a bore obstruction it has to drop, quickly. Until a powder is developed that doesn't build peak pressure in the chamber, that's they way it works. A random shell can't create new laws of physics.
I can absolutely believe a barrel with walls .012 thick could burst, and it probably wasn’t from a bad reload or obstruction. Remember, an aluminum soft drink can is .005” thick. I’d like to know what the factory bore diameter Is and what it is now with the overboring. I bet we’d be shocked at how much metal was removed from those bores
I can absolutely believe a barrel with walls .012 thick could burst, and it probably wasn’t from a bad reload or obstruction. Remember, an aluminum soft drink can is .005” thick. I’d like to know what the factory bore diameter Is and what it is now with the overboring. I bet we’d be shocked at how much metal was removed from those bores
Even if you know those two numbers, you do'ng know that it was concentric without actually measuring the thickness directly. Who is to say that the overbore was concentric at all points along the way?
You can be certain it didn't leave Perazzi like that. Perazzi goes, what might be considered by other manufacturers, overboard with barrel testing. They do a destructive test on one of every 50 barrels, hydraulically bursting it to determine psi needed to do so and location of burst.
Another thin wall split; honed to .739" with wall thickness .018". I don't know the load that was being used, but there is no ring bulge to suggest an obstruction
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