doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com making heavy barrels lighter

I have a set of 26" sleeved barrels on a vintage gun with minimum barrel wall thicknesses of over 35 thousandths. The only problem is that the sleeved barrels make the gun heavier than it should be for a gun with 26" barrels. Does anyone have any experience with making a set of barrels lighter, either by removing metal from the inside or from the outside to lighten up the barrels by a few ounces? Barrels with minimum BWT of 28 or 30 would be just fine. Thanks.

By far the easiest and safest way would be to have the gun overbored, opening it up about ten thousandths. Over boring is very popular these days on new guns and doesn't involve any of the pitfalls encountered with striking the outside of the tubes. If anything, over boring is likely to improve patterns and reduce felt recoil. I like Skeet's Gun Shop in Talequah, Oklahoma (918-456-4749) for this type work.

Rich, might be just a question of proper balance...I would try that first, I know this will add a bit to the overall weight but once properly balanced it might not be that noticeable...for me taking out metal would be the last option, I'd always take the cautious approach, you can also look at lightening up the forend and try and balance it that way.

Claudio

Joe and Claudio, Thanks very much for your thoughts on this. I want to use this old gun as a woodcock gun and, at 7 lbs., it just weighs more than it should with the 26" sleeved barrels. I have heard good things about Skeet's from my gunsmith too.

Any way to add any weight in the stock to balance it more?

Without getting my book of figures and a calculator out I tend to thinking that taking 10 thou off the inside diameter is not going to make a significant weight reduction.
I would be weighing the 3 gun component parts and comparing the weights with other guns of more suitable weight.
It could be that you have a big solid action that someone sleeved to a short barrel length rather than a light action with a unnecessarily heavy barrel set.
Some vintage guns were made HEAVY, some light as wands.
As CJO says, balancing the gun can make it feel much lighter.

Claudio just gave you the best advice you are going to receive on this forum. Shaving a few ounces off of a 7 pound weapon does not a woodcock gun make. If you are content to carry a 12 gauge that weighs over 6.4 lbs. through the alders, you are not concerned with weight but balance. I believe Trevallion wrote a series of articles for DJ on adjusting the balance point with weight. Throwing money at a problem does not always get the best result.

Thanks for the advice. Much appreciated.

I think a gun I had bored lost 2.5-3 ounces by removing .010 from the bore but that was for a 30" gun. It's more complex than a straight weight loss because small barrels loose less and bigger ones loose more. Think about the diameter of the bore. A large diameter barrel with .750 bore will loose more weight, metal reamed out, than a tight bore like .710 for the same amount of reaming. Mike O did mine and he did a very nice job.

Sometimes you just can't get there from where you start at. Easier way to get a 6 pound grouse gun is to drop down to a 16. Heck at most grouse shot ranges an ounce is more than enough shot because my grouse seem to be gone in a flash. A thirty yard grouse shot where we use to hunt would be a once in a year or longer fluke. A 16 with two fairly open chokes holds a lot of appeal for early grouse.

It's not too easy to make a gun significantly lighter. I'd find another gun.

Steel has a weight per cubic inch of approximately .282 lbs. In enlarging the bore you are of course not going to enlarge the chamber & only the small end of the cone. With a 26" barrel roughly figure you are going to enlarge 22�" of it. Assume a .730" bore enlarged to .740". For a not absolute, but close, figure take .735 x Pi x .010" x 22 � x 2 to find the CuIn. This gives 1.04 CuIn. Multiply by .282 to find pounds then 16 to find ounces. Result is 4.7 ounces for a .010" enlargement. You would of course only reduce the wall thickness by half the enlargement, assuming centered, so would leave a .030" wall. This would drop the 7lb gun to around 6 3/4lb.

What was the original weight ?

Do you mean prior to sleeving? Current weight is 7 lbs.

One way is to remove the ribs, install two small bridges between the barrels following the Alex Martin Ribless model.

According to one of the Brown family gunmakers, who built the gun for Alex Martin, leaving out the ribs removed a 1/4 pound off the front where it matters most. It also did away with the hidden rust trap between the barrels.

If you absolutely must have a rib you can fit a carbon fiber snap-in rib as a top rib, weighing some 30 grams.

It is a thought for those who are not addicted to ribs.

2-Piper, Many thanks for the math. Good to know. All the thoughtful comments have slowed me down a bit. Good to think things through.

2-piper I love math and that explains it so well. I need to get my barrels out and figure out if we took .010 out of the wall or I just had him open up the bore .010 which would be half the metal removed. My need was to remove pits not lighten the barrels. The barrels were 30" long so I bet it was just open up the bores.

Too many projects to keep them all straight. I have noted several guns felt slightly lighter after having the bore cleaned up but .005 takes care of most pits I have had removed. Or to put i t another way if the pits are much past .005 I try not to buy the gun in the first place.

After over boring the barrels you might find it desirable to hollow out the buttstock some to balance it. If so, another couple ounces might be eliminated.

Folks I had a senior moment, sorry about that. I was figuring for taking .010 from the diameter so the .735 (Midpoint of metal removed) should have been multiplied by .005" rather than .010". Thus actual weight removed would be only half what I said or about 2.35oz. My figures were for removing .010 per side or .020 " from the bore diameter. These "New" figures are very close to what you remember Jon.
Thus with just the bore enlargement of .010" you are looking at closer to 1/8 lb rather than � lb. While I am not in grouse country I did on one occasion do some very good shooting on quail & some woodcock with a 12ga J P Clabrough with 28" damascus barrels @ a weight of 6 lb 14 oz.Balance of the gun & fit just seemed to be perfect for me & it didn't feel that heavy. I was however a bit more physically fit at the time than at present.

I thought I always have regarding sleeved barrels being "heavier" is: are they really? I realize it all depends on the barrel profile but it seems to me that it is just as likely, if not more so, that such new barrels are closer to the gun's original weight distribution.
Any thoughts?
Jeremy

One problem with overboring .010: You just took your gun out of proof.

I'd echo the suggestion that in the long run, the best option might be to trade into another gun that's lighter from the start.

I may have missed it, where is the current center of balance for the gun?

Did you get the gun sleeved or did you sleeve it? (if you sleeved it what was the weight before the sleeving?)

Does the gun currently have a butt pad and if so what kind is it?

Leave it alone! Particularly so if it is shooting straight. You start screwing with the barrels you might as well take a hammer to it. If you don't like it trade it off for a different gun.

Rich only stated this was a Vintage gun. He did not list country of origin or where it was sleeved. If it is a US gun, Sleeved in the US, it was Never "In Proof".

"sleeved barrels being "heavier" is: are they really?"

Depends on what tubes are installed and what profiles are chosen. Modern high strength steels can give light and strong barrels assuming the installer wants to do some lathe work.

Richard, I have done a lot of research on shotgun handling, particularly, quantification thereof. I am working on a similar project, except a SXS sporting clays gun. I'll offer to share theories and learnings if you are so inclined.

Research tells me that handling fit should be thought of much like stock fit. The dimensions of handling are weight, balance (teeter-totter point), unmounted swing effort and mounted swing effort. We have weight. We need the length in inches from the teeter-totter point to the (front) trigger. I can SWAG a unmounted swing effort from the data base and calculate a SWAG mounted swing effort. If you have access to a typical Brit game gun you can feel the handling of a profile of about: 6 1/2# weight, 4 1/2" balance point to trigger, 1.45 unmounted and 6.4 mounted. A M-94 Winchester carbine is a fair surrogate for a game gun. If you don't have access to either of those, describe a gun you do have and I'll SWAG it.

2-p gave good info on weight change. With original balance, we can calculate new balance and new swings for various proposed weight and weight location changes. BTW, balance is not some magic number. It is a characteristic of each gun and can be changed by weight change or weight location change. The number should be what you as an individual shooter like/shoot well.

If you think this is helpful, post back.

DDA

That sleeved barrels "ruin a gun's balance" is a myth. The sleeves can be bored and struck to whatever the shooter's heart desires and his wallet will pay for. The far bigger problem is communicating to the gunmaker what is desired. I am currently working on what we need to tell the gunmaker to have a reasonable hope of getting about what we want.

DDA

I agree with Rocketman, a sleeving job by a competent gunsmith can mimic original gun balance. Kirk Merrington replicated the original proof weight of a pair of barrels on a Belgian near perfectly and the gun came back balancing beautifully.

With respect to weight removal from the barrels, I had a 12 proofed Greener hammer gun that had .783 bores as a result of extensive honing. Although it still had acceptable wall thickness, it was extremely light and whippy on the barrel end and stock heavy. My only point is that you can remove a significant amount of weight from the barrels through honing, but results may be somewhat unpredictable.

My old Omega weighs 3.5oz so if you have a heavy wristwatch you might want to just take that off and save the bore job.

just a thot

Rocketman,would you please expound further on SWAG.

Thanks for the comments. My gun is away for a stock repair and I won't have it back for a while. For a 12 gauge upland gun I like a carry weight between 6 1/2 and 7 lbs.. Lighter is nicer, but I have carried a 7 lb. gun all day. Rocketman, I am very interested in your research and in Miller's math on metal removal. I will have to wait to get the gun back in my hands to think through the balance issues. I have an English game gun, 6 lbs. 10 oz., with sturdy 28" sleeved barrels. According to the maker's records, it was originally 29 1/2" Damascus. All I know is that for me it mounts with a smoothness and balance that I have only rarely had in my hands before. It almost seems to mount by itself, like a gun that led Nash Buckingham to say that he had a gun that was so good that if you took an afternoon nap on the edge of a field, you could wake up to find a dead pheasant next to you that wasn't there when you fell asleep. I have had 2 English guns in my hands that balanced/mounted like that and one Lefever that did the same. On the question of whether to hone my 26" sleeved barrels, I will have to wait until I have it back in my hands and can consider all the good comments made on this board. I have no idea who sleeved my gun, although it is a very nice job. Also, I have no knowledge of the original barrels, Damascus or fluid steel, because there are no factory records. I won't sell it to get another grouse/woodcock gun, because it is a very special Lefever - a unique special order gun with magic game scene engraving and weird, but interesting mechanics. I am just whiling away a little time in the off-season dreaming about making it a little more enjoyable to carry. As is, at 7 lbs., it would work fine for me. At 6 3/4 lbs, it would be an even better carry weight. I would go for that, if the balance issues can be worked out. Anyway, you all have given me a lot to think about and consider when I get it back in my hands. Thanks very much.

I have a pretty reliable program at work that estimates weights. I can double check the math here to see where you'd get from honing, but if it were me, I'd be hesitant to mess with a well balanced old gun.

All due respect and no offense meant, Dan, the results are predictable. That few bother to do the math prior to cutting does not indicate that results are not predictable.

The bigger problem that I see is so few actually know what they really want. Tharin lies the advantage of quantified handling profiles.

DDA

Interesting to hear that the gun in question is a Special Order Lefever. I'd love to see some pics when you get it back. There was a thread on Lefevers about 6 weeks ago where the discussion went to frame sizes of 12 gauge guns. I took some measurements of several Lefevers to see where the weight reduction was in those with lighter weights. See my last post in this thread to compare with the dimensions of your frame:

http://www.doublegunshop.com/forums/ubbt...true#Post478357

It could well be that your gun was either mid-weight or on the heavy side before it was sleeved. I see a range of over 2 lbs. in 12 gauge Lefevers I've owned. Unfortunately, as you probably know, it became fashionable for people to cut down barrels of long heavy doubles in a vain attempt to remake them into upland bird guns. The results are usually not so great, and the value of a vintage double is greatly reduced in the process of attempting to convert a heavy duck gun into a light upland game gun.

To get to where you want to go could involve a costly process of removing weight from the barrels, stock, and frame to achieve weight reduction and great handling dynamics. Of course, removing metal from the frame to approach the dimensions of those rare light weight 12 ga. Lefevers would involve removing some of that lovely engraving. So in the end, it may be best to utilize this gun for clay target shooting where the bit of extra weight would be welcome in recoil reduction. As an aside, you may be able to detect whether the original barrels were Damascus or fluid steel by closely examining the barrel flats of the original breech section, assuming the original set was used for the sleeving job.

Just cut 6 inches off the barrel length
It will be lighter

Or hone the mass out of the barrels but DO NOT lengthen the chamber
as it will destroy the gun !!

Y'all starting to get my point??

Get the correct gun for the job, or find a second set of barrels that were NOT sleeved

Mike

I double checked my math. What I said was "Close" was to take Pi x D using the mid point diameter as D. For my double check I figured the area of a .740" diameter minus the area of a .730" bore. An old Machinery's Handbook gives the weight of steel (No specific alloy given) as .2817 lbs per sq inch. I rounded to .282 lbs/sq/in. Using the same criteria of estimating that about 22.5" of both barrels would be enlarged & then converting lbs to ounces it took 9 decimal places before there was a difference in the two methods.
The simpler method of using pi x .735" x .005" thickness gave 2.344168473 oz.
Using the area of .740" minus the area of .730" with all other criteria the same gave 2.344168474 oz. That is thus the amount of weight you would be looking at in removing .010" of steel from the bore of a nominal 12ga bore. Considering bore sizes normally found in 12 gauge guns & for a 26" barrel length you are looking at the range of 2� to 2� oz for a .010" enlargement.
Rich, I know what you mean by that "Special Feel". To me my Birmingham built J P Clabrough has it. It has 28" Damascus barrels with a weight of 6lb 14oz & carries Nice. I have also however done some good shooting, For Me, with a 7� lb FE Lefever which had a set of 26" steel barrels built which match the weight of the original 30" Damascus ones. These barrels were built from scratch so I still have the originals.

Scientific Wild A$$ Guess. I this case, however, we have a data base to work off of. So, we can/should be able to make decently accurate estimates. Knowing the weight, balance, barrel length, and stock LOP lets us look up comparables.

DDA

Thanks Rocketman,always good to expand my vocabulary.

Hi all;
I did a bit of further checking. My close Estimated method of taking the median diameter of the old bore size & new bore size times Pi times thickness of metal removed "Per Side" times length of bore thus enlarged is actually not a reasonable estimate. It is in fact Spot on & 100% accurate for the Cu Inches of metal removed. Sort of surprised Rocketman didn't call me on this one, guess he was just being his normal kind self.

Quite often there is more than one way to figure something. For instance when I figure the area of a circle I normally use PiD�/4 rather than the normally quoted PiR�. Answer is the same both ways as R = D/2 then R� = D�/4.

2-p, I knew your math skills and believed you would provide the needed corrections. No need to correct a self-correcting "system." ;-)

DDA

R'Man;
Thanks for the compliment. My math skills are nowhere near yours though. During my working career as a machinist outside of just plain arithmetic I used more trig than anything. Trig of course doesn't come into play here.
I had just assumed that taking that median diameter times half the metal removed from the diameter differences would be a close approximation. had not realized it would in fact be exact.

I appreciate all the comments here and deeply appreciate Rocketman and 2-Piper's math skills. My worst subject. A passing grade for yours truly was an act of charity by my high school math teacher!

My reports think I'm from the stone age calculating on my trusty HP-41CX. (formerly C then CV)...as for area of circle formula I prefer to cut to the chase and go with pi r2 the only issues I have is dealing with inches as I work in decimal feet. 276' diameter tanks are a lot of inches

Ken;
I can't say for certain but I would assume when working with a tank that size you would not be dealing in cubic inches, but cubic feet or even cubic yards. the formula works identically for any unit of measurement as long as you keep all components on the same scale. Thus if you use feet for the diameter you have to also use feet for the length/height of the tank.
As to Pi xD�/4 versus Pi x R� they are of course the exact same formula. As R = D/2 then (D/2)� D�/4. When I am using this area formula I will normally be working with a diameter rather than a radius so I just Sq the D & divide by 4 rather than divide D by 2 & sq the result. Multiply by Pi either way. Exact same number of keystrokes on my faithful Casio Calculator.
I have absolutely not the Foggiest idea where that &#960 came from. I held down the alternate key & typed 227 & the Pi symbol came up. When I post every time it has thrown in that &#960 instead. I have gone back & edited & used the letters Pi instead of the symbol. The listing I have for these says to hold Alt & the Windows symbol but for ages I have only held the alt key & it has always worked. As a test I am going to try Alt & Win then 227 & see if it transports OK.
Test = π
Obviously that's not the problem, When I typed it in it came up with the Pi symbol plain as Day but when I send it comes out this GobbledeeGobble.

Miller,

If I were using your Casio I would most certainly end up with an incorrect answer. For better than forty years I've used nothing be HP calculators that utilize RPN (Reverse Polish Notation) logic. (X enter y +) to use a normal calculator like yours (x+y=)
I struggle. All good!!

It is certainly fascinating to see the turmoil a grade school level calculation can cause.

I suspect the root cause is that this is the "pie are round" contingent.

I hope none of you work for NASA

Well I never worked directly for NASA but I built or helped build a pile of test models that ended up in Nasa wind tunnels in my career. I once on this board made the statement that areas of bores were proportional to the Square of their diameters. Some very Brilliant Mathematician posted back they were not proportional to their diameters but their radius. Duh , since the radius is diameter/2 if they are proportional to one they are proportional to the other.
Sometimes you just have to get down & Basic to make people understand that you can work from the diameter same as the radius if you use the proper figures.

Ken;
Never did like those RPN calculators. I started also over 4o years ago (was one of the first machinists in our shop to have a calculator) with a "Normal" calculator & learned to use it. I got on the Casio's due to their trig functions. I worked with a lot of angles which were often given in degrees, minutes & seconds. The Casio was to the best of my knowledge the first reasonably priced calculator which allowed you to take a trig function directly form an angle entered as � ' " . Most others of the early times if I wanted to take the Sine say of 15� 30' I would enter 15.30 but would then have to convert to 15.5 before taking the function. The Casio was simply much easier to work with & once I got to using them I just stayed with them even after other makers upgraded to the same method of doing the trig. .

Actually what I should have said was that I'm glad none of you worked for me.

Bottom line was a poster here wanted to know how much weight he could remove by enlarging the bore of his Shotgun. I figured it for him. Any problem with that.??
I do "VERY HIGHLY" suspect you are not near as Glad I never worked for you as "I AM".

Miller,thank you very much for providing the figure of 4.7ozs per .010" of steel? It is a valuable piece of knowledge to use when evaluating vintage guns.

This is quite amusing. I wish we could conduct a poll to determine how many here think that Dr. Wanker has contributed more useful information than Miller. But I don't think even an overwhelming response in favor of Miller would do anything to deflate Dr. Wanker's egotistical self-image.

Better watch it Miller. Dr. Wanker gets pretty jaded about being wrong. He is very likely to pretend to IGNORE you if you get his estrogen level any higher than it already is. Speaking of rocket scientists, this is a brain-child who actually recently insisted that repeated soakings in organic solvents will do nothing to degrade the cellular structure of walnut gunstocks.

Why bother with the gun at all. If you never order the container of clay targets, you don't have to shoot at them. One of the very few things I wish for in this life is to get up each morning and working for Doc Wonko. I guess we can't have it all.

Justin;
I did make a slight Boo-Boo on that first calculation which I went back & corrected. That approximately 4.7 oz would be correct if you were removing the .010" per side. We were actually speaking of removing .010" on the diameter so it needs to be divided by 2 thus 2.35oz for a .010" bore enlargement from a nominal .730" bore. The approximation itself is not within the "Formula" but I simply had to guess where the point would be in relation to the forcing cone to determine the length of bore over which metal would be removed. The longer the cone of course the less will be the length of the bore you are going to enlarge.

I kinda questioned that...Glad you cleared it up...

Miller, thanks,I did catch that extension of the formula.

Well, WTS, I did work for NASA for awhile. It was a good experience, but not one I wished for a career.

AS for working for you ---- gee, I dunno. How about the other way round?

BTW, I care much less for the level of involved math than for the ability of people to use any math to solve a problem.

What say we raise the ante? What would be the moment of inertia of the removed metal? How would the removal impact the gun's weight, balance, and swing efforts? This is the set of calculations that I said above made changes to guns reasonably predictable. WTS? Anybody?

DDA

Both sides may land a few hits, but there are no winners to an internet fight, gentlemen.

Never worked NASA....close as I can come to that is working on vacuum chambers for testing satellites in outer space.

As for working for you.....the feeling is mutual. Hell, why would anyone need to work for you? You know everything....allegedly.

What I do know absolutely is that if I lived in so humorless a world as do most here I would certainly open a vein

have another day

Don,
I don't know about calculating the MOI of 2 oz over the length of 22 1/2" of barrels. But my experience suggests that the money to remove .010 out of the bores has a higher MOI.

I went thru these calculations and weighed the cost/benefit on a 32" Win 101 years ago. It had screw-ins, so the limit was about .010" out of the bore before the chokes became an issue. With such a small change in weight, I couldn't rationalize the cost. I just bought a 32" Beretta Gold E with very light barrels. Those new barrels came with a new action too. It was a much better move.

I have not read the calculations closely, but did they take into account removing weight from two barrels ?

Daryl;
Yes, Two 26" barrels. Not having the gun in hand I roughly estimated a 2 3/4" chamber & a 3/4" forcing leaving 22�" of barrel to have .010" removed from a nominal .730" 12 ga bore. Actual measurements could vary the outcome by a Teensy Weensy amount, but would be in-consequential at most.

Miller and Daryl,
This is very helpful. As a rule of thumb then, I will estimate that removing .010 of metal from both barrels will eliminate about 4.7 oz of weight. Can I assume that this figures in keeping the chambers, forcing cones and chokes intact? Thanks.

As I read it, enlarging the bores by .010" (.005" per side) will produce a reduction of approx. 2.35 oz.

Enlarging the bores by .020" (.010" per side) will result in a reduction of approx. 4.7 oz.

Redoak, That's the way I read it too. In other words, if the BWT is reduced from .035 to .025 in each barrel, the reduction in weight would be about 4.7 oz.

Rich;
That is correct. If you reduce the wall thickness by .010" then you will of course be enlarging the bores by .020". This was based on 22�" of the barrels being enlarged which would basically be from the cones forward. Since you were speaking of this for a Woodcock gun I assumed you would not want the chokes increased by .020" so would enlarge them as well. As Lefevers normally have long chokes if you leave them totally intact your gain would be a bit less, but probably still on the order of 4 oz (�lb).

Many thanks, Miller. That is very helpful.

Chuck, I'm neither pro nor con on the proposed question. My point is that it is quite possible to predict the outcome with good accuracy. 2-p's calculation for weight change is a good example of how a reasonably simple calculation can predict an outcome. Only the owner can know if the outcome is acceptable and worth the price.

DDA

I once knew a man who lightened a rifle by milling the action to the point of weakness and flexation...at the end of the day he saved the weight of two cartridges. Some things are hard to re-engineer, and there can be unintended consequences. Just my two cents.

The best weight reduction is to buy it in a 16g.
O.M

One of the most interesting posts that I have seen regarding doubles was placed on Shotgunworld, by Shotgunguru July 16, 2012.
It explained the concept of achieving optimal game gun balance when weight was concentrated at the action. He discussed how to weigh the gun components individually. It is something you should read.

Don Amos, Rocketman, has been acquainted with this concept for many years. He is the one who explained it to me when he spun a double of mine years ago on his turntable. When he explained the importance of where the mass is concentrated on doubles, and how that affected handling, it was just as if a light came on for me. Its all very simple, but if you've never thought through it all you don't really understand how two 6# guns can handle so much differently. I had read an article about Don and his MOI measuring device earlier in Shooting Sportsman but still didn't get it until we talked.

I agree that everyone who has any interest in how a doublegun handles should make the effort to understand that concept. BTW, having a large part of the mass concentrated in the action is not always what makes for good handling. It can be just the opposite, as I learned. I have a very lightweight .410 S x S with 28" barrels that I shoot well. I couldn't understand how that could be, as the majority of shotgun shells I go through are in a 9 lb. 3 oz. Perazzi. When he showed me how the mass is concentrated at the butt and in the barrels, and with the lightweight alloy receiver, I understood. With more of the mass being on the "ends" of the gun it slows it down a bit. He actually said that the turntable numbers on it were almost identical to a good English 12 ga. game gun.

SRH

volleyfire, with all due respect and no offense intended, I'd take exception to said article's precept. First, there is no such thing as an "optimal" characteristic for a gun. There will be one or more sets of characteristics that are optimal for one given shooter. As an example, there is no one optimal set of stock dimensions. Each shooter has his own. So it is for handling, no one universal set of optimal characteristics; each shooter will have his own.

Second, handling is characterized with weight, balance (the teeter-totter definition), unmounted swing effort, and mounted swing effort. It is impossible to "sum-up" handling with one characteristic. Length of pull does not define a stock. Likewise, balance does not define handling; it takes all four of the above.

Third, the term "balance" is often misused in an attempt to sum up handling. Subjective explanations are always suspect since two shooters would have to be "calibrated" to each other's subjective words to gain truly accurate information. For example, "This gun has perfect stock dimensions!" Perfect for who? "This gun has perfect balance!" Perfect for who? Is the reference to teeter-totter balance or to the subjective summative definition?

Stan gave a very good explanation; he truly "gets it." I'm just fleshing it out a bit. Fourth, if the weight were truly concentrated at the balance point the gun would require zero effort to swing unmounted and less than usual mounted. This is certainly not desirable, much less perfect/optimal.

Post back to discuss or for clarification.

DDA

Don, you just keep making it more difficult for me to poke at you but here's a try.

You might want to replace " balance (the teeter-totter definition)" with "weight distribution" since all the bean brains already have internalized "balance" albeit in a likely misguided way, and apply their misconception to your better (maybe) methodology.

I applaud your move to a no absolutes position. And there are even no absolutes for an individual. Different horses different courses etc.

have another day

Gee, WTS, I'll take that as a compliment. ;-) I appreciate your humor and try to return it.

Balance (teeter-totter) is the summation of weight and distribution; weight times distance from the point where weight times distance on each side is equal. "Weight distribution" by itself is a wee bit open to interpretation.

+1 on "horses for courses."

If there was an optimum for any of the characteristics of guns (weight, balance, swing effort, LOP, drop, cast, pitch, barrel length, forearm size/shape, grip size/shape, etc.) then there would only be that number/size/shape in use as everyone would shoot it best. If all of the characteristics had optimums, there would be only one standard gun and we would all never miss. There is a rumor that WTS bought the prototype of this gun at great cost and has selfishly hidden it away. ;-)

DDA

Don,

I cannot tell you how happy I am to find out that you are the originator of this concept. As you could tell from the questions I asked, it was apparent that the idea was one of importance that I could appreciate but not fully understand from the information given. It could not be truer that everyone needs and wants a gun with a slightly different set-up. But I would very much appreciate you summarizing the principle, either here or in a private message.
Thanks Stan.

Steve

Rocketman is our current guru, but Gough Thomas had something to do with it...

Say not sure if this helps but in reviewing a post on guns on pegs 2017 a short clip on a barrel maker making sxs barrels from a single billet claimed stronger and lighter replacement barrels may be worth a quick search
Rich.

Volleyfire, following is a short explanation of handling.

Stock dimensions fit the gun to the shooter�s physique. Handling fits it to his strength, muscle speed, hand placement preference, and shooting style. As we use differing stock dimensions for differing shooting situations, so do we use differing handling. The objective of any fit is to better adapt the gun to the individual shooter. Better fit may result in higher scores and/or more fun.

Weight, balance, unmounted and mounted swings are the four dimensions of handling. Swing is the dimension that tells us the effort needed and/or time required to point the gun in a differing direction. Moment of inertia is the measurement that tells us swing effort. MOI at balance point is for unmounted swing effort and MOI at butt is for mounted.

MOI measures the resistance of an object to changing rotational velocity. The gun resists starting swinging proportional to its MOI. It resists stopping swinging likewise. Increasing MOI indicates increasing effort to start swing and stop swing.

Following are three examples of averages:
Average 2"-12 Bore Game Gun weight = 5.37#, balance = 3 5/8 " to trigger, unmounted swing = 0.95, mounted swing = 4.75, gauge = 12-2", avg bbl length = 26, avg LOP = 14 1/2"

Average Game Gun 6.50#, 4 1/2", 1.45, 6.38, 12-2 1/2", 28, 14 1/4

Average Light Pigeon/High Pheasant 7.21#, 4 5/8", 1.67, 7.46, 12-2 3/4", 29", 14 3/4"

MOI at balance is measured on a constant torque turn-table driven by a bob-weight. The gun is clamped in a vise atop the turn-table. One revolution is timed and MOI calculated via an engineering formula. MOI at butt can then be calculated via the parallel axis theorem.

Questions?

DDA

Thomas and I were/are afflicted with two of the same maladies - mechanical engineering and an obsession with guns. Thomas published his work with a torsional pendulum in the 1960's. I never heard of him or his work until I started posting data in the late 1990's. In the resulting firestorm,someone pointed out, in my support, that Thomas had published this same sort of work. Thomas was disappointed that so few Brits were interested in the technology of guns and shooting. He did only a few guns to satisfy himself. So, I confess to following in his footsteps, but with a greatly expanded data base and broadened application.

MOI machines are calibrated with "bars" of calculated MOI.

DDA

Rich, one piece barrels have been made for some years. They may ultimately have a price advantage. Light weight is not always desirable. The handling characteristics of the barrels need to be taken into account during the gun's design.

DDA

That is absolutely not true. I sold the gun to a well known manufacturer so that they could suppress its existence and insure continuing sales. Just like the water -> gasoline pills.

Don -
I, of course, always admire the pursuit of knowledge but in some instances I'm bothered by the collection of "data" for the apparent purpose of collecting data. I find the gun thing particularly troublesome in that regard since nothing more than wood density can affect the data to a likely demonstrable degree and stock conformation is not quantified - straight grip, PG, MC, splinter, BT, etc. AND gunmakers for maybe century or so have already derived empirically a set of parameters that can be generally applied or tailored to a specific individual. So just what purpose is it that your data serves?

inquiring minds, etc

If a person shoots multiple disciplines, and a broad selection of game, the handling parameters of various shotguns play a roll in their success.

No point in adding a gun into the mix "you" couldn't possibly shoot well. Or, worse yet, buy it, then spend a king's ransom trying to make it into something it's not.

I want to thank Rocketman for taking the time to explain the complexities of his turntable measurement technique in private messages. It is a very interesting subject, and Don is a great gentleman for going the extra mile to help the inquisitive.

Clapper, +1. Above is the point of understanding a gun's handling and what can reasonably be done about it.

Steve, thanks for the kind words.

DDA