Let's say you've been looking for several years and finally found your grail gun. All the right options, proofs and dimensions, very good condition, original, original case, etc. but with barrel wall thickness at only .019 and .020... Let's say further that the guns seems to be priced correctly, maybe even well. Would you "pull the trigger"?

If the thin walls are in the upper third of the barrels they are not going to be a problem. However, if they are ever dented or need honing there is not enough thickness to fix them properly. And should you ever decide to move them on they might make a sale more difficult. I would be more interested to know wall thickness in front of the chambers and for the first half of the barrels--that's where pressures can be a problem.

Shall we presume the subject gun to be a 12 gauge?

As you go to smaller gauges the pressure increases and wall thickness becomes a critical issue.

Not an expert in barrels but this is my 2p's worth. *assuming its a 12 bore not needing any work.

.019 and .020 in its self would not be a deal breaker in a gun I simply wanted to own use and enjoy, in fact as you have alluded to it might mean a otherwise unaffordable gun is well priced as long as you shoot appropriate loads and look after it there is no reason why the gun wouldn't last your lifetime and perhaps longer again.

Thin barrels are inherently less strong, ie more prone to dents and should you develop a dent your more like to end up with a worrying thin spot.

Just don't convince yourself its an investment, its an indulgence.

http://www.vintageguns.co.uk/articles/thin-barrels/

I've been collecting Fox doubles for almost 50 years before most practical gauges and instruments were available to the average shooter/collector. Back then and now, I guess most of us would base our buying decision on the condition of the gun, price and need or desire.

I have an early style A grade 12 gauge Fox, SN 7983 that I have owned for a little over 47 years and shot easily several thousand rounds through it. Back when lead could be used for waterfowl, 2 3/4 inch magnums were my choice for ducks and geese. In the last few years tho about the heaviest I shoot out of the old girl is 3/4 ounce.

Your question poses another good question: If you've had a gun or guns that you have shot a lot and measured the barrel wall thickness and found it was around 0.019 inches or a little less, would you quit shooting it?

Yeah, good question.

Jolly

Would sleeving be an option? Or occasionally shooting 12 gauge shells, and having a set of Briley sub gauge tubes for some of the shooting? I don't know if that would make it less attractive to you.

Oh, or reload low pressure loads- one of my favorite 12 gauge loads is straight out of the Hodgdon manual- 1 oz at 1125 fps and 5400 psi. There's one with PB powder that's only 3400 psi according to the manual.. that should be very easy on thin barrels.

I once had a gun which I discovered later had 0.19 barrels. After that i loaded low pressure for it and it performed well, but i just could not get over the thought of the thin tubes. It made me paranoid, and i got rid of it.

No.

SRH

No. Just no room for anymore barrel work. If dented the dent will be very difficult to raise without more metal being removed. Heck just polishing for bluing might cost you a thousand or two. If .019 worries you now how does .018 or .017 sound?

On top of that I just don't think barrel wall thickness measurements are precise to .001. What if the measurements is off by .001, .002 or even .003? Have you measured them yourself and know for a certain fact they are as stated? I take my measurement system's results with a grain of salt. So I would pass. Better to pay more for a gun with more life left in it.

Yes, it is a 12 gauge.

Really appreciate the opinions!

You guys have hit the nail on the head. For me with many of these guns, we're caretakers. We have it for a while, use it and care for it, but eventually due to whatever circumstances it changes hands, and when/if I tire of it (before dying?!), I'd like to be able to sell it.

It's not my dream gun with barrels that thin. Can it be shot with low pressure loads? Probably. Would I? Probably not. Too many guns in the world to risk life and limb. Well, that's a bit strong, but if anything happens to the barrels it would probably be a total write off.

One word on this "LOW PRESSURE" bit. All you folks riding this low pressure "Hobby Horse" are talking about maximum chamber pressure. Take two loads with same overall ballistics, say 1oz @ 1200 fps with pressures of 10K & 7K in the chamber. That 10k load is almost certain to have a slightly lower pressure down there where the thin spot is.
The only problem with that .019" assuming as previously stated it's in the forward third of the barrels is from handling damage, not from the shooting.
Do you have a gun with good dimensions over the chamber & first 9-12 inches of barrels but thin toward the muzzles you want to shoot. Shoot a moderate shot load with moderate velocities using the fastest powder which will stay within proper pressure levels at the chamber. DO NOT think you're babying the front of the barrels by dropping the pressures at the rear unless you also drop the total ballistics of the load. Do not use any of the so called slow burn Progressive powders if you're truly concerned about the Front End of the barrels.

I'd pass.

The other thing you might consider is how much does your dream gun cost you with good wall thickness, and also, at what stage do you stop worrying about wall thickness? If they were .020 or .023 would you have the same concerns? I don't know.

At 019 I do not believe it would stand in my way. But we want to know what is this dream gun?

Nosirree bobcat.
JR

I am aware of both Parker, Lefever and Fox barrels that were struck that thin in the factory! These are not uniformly thin but usually a section found on the side or bottom of the barrel. And yes, I'm satisfied the bores haven't been honed or the barrels refinished. Very few guns have had their wall thickness' accurately measured. I recall a very nice Belgium boxlock I was attracted to in Tulsa. Price was certainly right and everything looked right. Fetched my wall thickness gauge and ran it up the bores. A whole lot of the front end measured .011 or thereabouts! Amazingly, the seller seemed to instantly develop a hearing problem....obviously, I passed....and ran!

your dream gun if barrels were .019 [Re: swoobie]
Demonwolf444 Offline
Sidelock

Registered: October 18, 2014
Posts: 174
Loc: North Yorkshire. England. Not an expert in barrels but this is my 2p's worth. *assuming its a 12 bore not needing any work.

.019 and .020 in its self would not be a deal breaker in a gun I simply wanted to own use and enjoy, in fact as you have alluded to it might mean a otherwise unaffordable gun is well priced as long as you shoot appropriate loads and look after it there is no reason why the gun wouldn't last your lifetime and perhaps longer again.

Thin barrels are inherently less strong, ie more prone to dents and should you develop a dent your more like to end up with a worrying thin spot.

Just don't convince yourself its an investment, its an indulgence.

http://www.vintageguns.co.uk/articles/thin-barrels/

I generally listen to Joe Wood but this guy hit the nail on the head....I bought a Boss a few years ago and dove hunt with it but the thin I think .018 is near the muzzel.
I don't think it was ever real thick to begin with........ and yes for considerably more I could have gotten one with thicker tubes... But I own a Boss

Pull the trigger

Other than perhaps trivial information pertaining to barrel wall thickness, these comments are useless as regards whatever decision Brother Swoobie may ultimately make with his "dream gun"; but I was visiting with Buck Hamlin earlier this week when this very subject arose. Buck said that some years ago, the now departed Lanny Samson came across a thoroughly well-used Damascus barreled Lefever (didn't remember grade) with a burst right barrel (just past the forend tip)that he had purchased for parts; and he commented to Buck how extremely thin the tube was at the rupture point. As Buck was conducting strength testing on Damascus barrels at the time, Lanny sent him that Lefever with the understanding that Buck would run heavy loads thru the left barrel until it failed. On receiving and examining the gun, Buck was amazed at how hard this gun had been used, as portions of the original stock wood was simply worn away from having been carried and used. Barrel wall thickness at the rupture point was .010; and Buck was convinced, based on the condition of the gun, that the gun had simply been shot so much that barrel walls had worn thin from shooting.
So with the intent to blow the left barrel, Buck measured bore diameter and started his experiment with a box of 2 3/4", one and five-eights ounce short magnums; and the original 2 5/8" barrel chamber was not lengthened. The left barrel digested that box of shells just fine, and with no change in bore diameter; so he then moved to phase 2 of his experiment. The chamber was lengthened to 3", and 25 rounds of 1 7/8 ounce magnums later the barrel remained intact with no measured changes to bore diameter (all loads used were factory rounds given to Buck by duck/goose hunters to make sure they didn't accidently violate mandated steel shot laws; all shot was lead and mostly lead #2 and BB sized pellets); so Buck now moved to test phase 3. The left side chamber was now opened to 3 1/2" and gun subjected to 3 1/2" two and one-quarter ounce lead turkey loads; the left barrel ruptured after only a few shots. Buck then measured barrel wall thickness at the rupture point, which was almost perfectly aligned with the bursting point in the right side tube; and wall thickness there measured .010 also. Obviously whatever strain this particular Damascus tube could withstand means nothing as regards application to another, and perhaps even thicker tube; but having this information would certainly make me feel a bit easier about shooting a gun with a barrel tube almost twice as thick provided that barrel was judged sound and low pressure loads were used. But regardless, experiments such as described herein clearly indicate that good quality Damascus tubes are capable of far more abuse than any members here would ever consider dishing out.

Sure I would, with the following caveats:
1. My "dream gun" concept has changed a bunch of times in the last 30 years.
2. Your dream may well already be in the safe, with just a bit of gunsmithing.
3. Recognizing that even modern barrels are very rarely perfectly concentric, I would want to personally measure the wall thickness, carefully rotating the tube to identify thin spots. I have confidence in my equipment and the reproducibility of my numbers.
4. If the .019" was past 18" - 20" from the breech, with adequate wall thicknesses to that point.
Scroll down toward the bottom here and you'll see the pressure at 18 - 20" using Black, Bulk, Dense, or Progressive Burning powders is about 1000 psi or less. Some of the curves are pressure/time and others are pressure/distance.
https://docs.google.com/document/d/1F2sQuPm05IE4VWYYnCkvuXmYEzQoWd_SQgaAfUOZEFU/preview?pli=1
5. And I'd still use low pressure loads

No.

Too thin.

If it was a British gun, and it was in proof, yes, I would buy it.

What constitutes a "dream gun"??? If a dream gun is one that I would shoot better than all the rest, then likely yes. If not, then probably no.

OK for a gun used quite a bit with low expectation for remaining value.
Not OK for a brand name gun (Boss, Purdey, etc) which high value is likely to stay over time.
I think twice before buying anything below 25mils, and probably not at all if at 20 or below.
It's always possible to dent barrels, and low wall thickness makes the denting probabilities higher as well as the consequences more dire. Not to mention the safety part that should be OK as long as the thin spot is much ahead of the fore-end.
Something not to forget is that corrosion can be nasty under the ribs, and that it is not possible to measure thickness there.
The thinner the tubes, the scarier that becomes.
Best regards,
WC-

So is it original or does it have .019" barrels or both?

Drew;
I have scrolled down to the page in your link which compares pressures for 32 grs ballistite vs 42 grs Schutz, both with 1 1/8 oz shot. The Ballistite load gives 1232 fps @ 2.9 tons (8624PSI) while the Schultz gives 1220fps @ 1.69 tons (4558PSI). However at the 18" & 24" points the ballistite load has .33 tons & .21 tons while the Schultz load has .55 tons & .32 tons.
Now lets assume I have a sound gun in good condition with adequate wall thickness in that important area at the chamber & first 2/3 of the barrel but am concerned because it is thin from 20" on to the muzzle. Is there really any valid reason I should chose the Schultz with its considerably lower breech pressure over the Ballistite load with its noticeably lower Muzzle pressure. With the nearness of the ballistics of the loads both are going to be very close to each other in overall pressure, it's just distributed differently.
Again I feel the entire picture needs to be looked at, not "JUST" the maximum breech pressure.

I think you've made a valid observation Miller. The pressure/distance curve:



Ballistite, Cannonite and Walsrode were dense smokeless; Schultz bulk smokeless. The choice of 32 grains of Ballistite is confusing, as 24 grains is the published load for a 3 Dram equivalent; 26 grains for 3 1/4 Dram.
Alfred Nobel's 'Ballistite' was introduced in 1887, patented in 1888, then ‘Sporting Ballistite’ (for shotgun shells) was patented in 1889, but not released to the trade by Nobel’s Explosive Co. until 1895. The published summary of the Trial states ‘Ballistite’ rather than ‘Sporting Ballistite’.

PLEASE NOTE that all the curves essentially meet at 6"

The issue of shotgun barrel strength and wall thickness is complicated, and tensile strength is only a part of the equation for estimating bursting pressure.

Barlow's formula P=2 S 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.

Barlow’s refers to a pipe capped at both ends with a static pressure (a pressure cylinder). Shotgun barrels are not designed to be pressure vessels as one end is open and the pressure rises and falls quickly (milliseconds). I've discussed this issue with both a mechanical and metallurgical engineer and neither is aware of a good bursting pressure equation for shotgun barrels.

Burrard used 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

American Standard:
http://www.smt.sandvik.com/en-us/materia...rican-standard/

Ignoring the effects of repeated high stress has a long history of disaster .

The thinner those barrels, the higher the stress. Cycling metal near its yield limit puts you in the range of a possible low cycle fatigue failure.

While a discussion about ultimate strength is relavent too, if you are firing one shot, I would be more concerned with knowing if the stresses were high enough to look at a low cycle fatigue failure. That's a much lower stress.

So, an old relic was shot to pieces, neglected until pitted, rubba-dubbed to make it sparkle,then reamed out to extract some salvage value from it, and it's still someone's "dream gun"?
I'd say that it was definitely not their (the seller's) dream gun. At least not anymore it wasn't.

The "name", model, or description might be a dream gun, but not this actual gun itself.

"Buy the gun, not the name."

We still don't know the make or model of the "dream gun" nor do we know why Buck Hamlin would wait until his test gun blew up before he measured the wall thickness. The gun is crap, don't buy it.

I believe I would pass, also. Drew pointed out a simply wonderful fact that few peoples dream guns remain so, forever. Mine have evolved, over the years, and guns I believed were the dream came and went. I still quest, but, I'm a bit jaded these days, as well.
.019 wall isn't a lot of material, just from an impact resistant point of view, much less a progressive powder point of view.
Good luck, at any rate, and do keep us posted on what you do. There will be other dream guns, if that makes you feel any better.

Best,
Ted

The heart of a shotgun is the barrels. If the barrels aren't great the gun isn't great. Pass on this dream.
Jeff

Well a potentially difficult decision was made a bit easier for me - the gun just didn't fit me at all.

It was a very nice drop-lock.