over the years, many thousands of pre ww2 double guns were made with chambers less than 2 3/4", which is the standard length for most shotgun shells these days...

have noticed that if gun with lengthen chambers is of english make, then some here make a big deal about it...


why is that? so long as there is sufficent metal left in front of the chambers for safe shooting, what difference does it make?

If you don't like it, there are pens that can touch 'em up? Just kidding Ed, if 2 3/4" is good, three is better? Is it worth closing the sale by saying, and you can get shells for it at wallymart?

Ed, if you haven’t noticed yet, originality is prized among collectors of vintage guns. None more so than American collectors of American makes. Lengthening the chambers is messing with originality, regardless of being safe or not. It’s not any more complicated than that and the quest for originality covers all aspects of the gun, not just the chambers.

Why lengthen the chambers if you can shoot 2 3/4" low pressure shells out of a 2 1/2" chamber? Per these two threads and Sherman Bell's articles, there is not that much pressure increase.

https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=34376
http://www.16ga.com/forum/viewtopic.php?t=1983

On the other hand, an acquaintance who was close to the late Cyril Adams had this happen to him after he lengthened chambers from 2 1/2" to 2 3/4".



He had this to say: "I bought the gun for me as it is a non rebounder. I did not have it proofed because I never intended to sell it. When it arrived I observed that the chambers were very thin compared to most. I recut the chambers to 2 3/4. I only shot light 28g shells through it and it performed flawlessly for over 500 rounds. I was preparing for the Adam’s cup and could only find 1145fps 32g loads. It let loose after the 15th one."

I just lengthened a GECO Belgium gun to 2.75, I also opened the chokes to Skeet/IC
It is my gun, for me to shoot, and if I hurt the value, that is OK to me,
The chambers are stout.

I do load 2.5 inch 16 gauge ammo, for my old Kreighoff drilling and my Win Model 12s
but I have flats upon flats of 2 3/4 ammo.
I am happy

Mike

I like the subsequent purchaser argument put forth previously. I once owned a hammer gun proved as a 12 with 2 3/4 chambers and then successively enlarged to 10 bore with 2 7/8 chambers, presumably by various generations of American gunsmiths. The guy I bought it from was insistent it was a 10 and did not believe it had started life as a 12. When I sold it, it was only with full disclosure of the modifications.

Most French guns have stout chambers and muzzle wall thickness. While you should always measure (Gene’s anecdote about a guy who KNEW the chambers were thin, and lengthened them anyway, demonstrates that not everyone who has gun smith tools should be allowed to use them) it has been a long time since I measured a French gun with less than .050 wall thickness, and a bunch of metal in the chamber/forcing cone area.
If you find that, you could certainly consider lengthening the cones, or, the chambers, or both. I’ve done it, told people to do it, and, sometimes just not done it, even though I think I could. Depends on the gun and the use it is going to get. I have a single, French, 2 1/2” 12 that I am using as is, mostly because there is a flat or so of 2 1/2” stuff on the shelf, and I intend to chase pheasants in the cold with it. That, and I’m cheap, and hope that 2 1/2” ammunition returns before I’m dead.

Might not, though. We will see.

Best,
Ted

Too easy to find proper loads on the internet or roll them yourself. And as we have covered many times it is not how long but how high pressure they are that is important. A 600Jr and a hundred dollars of stuff will make a lot of proper loads for shorter chambered guns. So why ream them out and hope they still have enough metal to shoot too high pressure loads?

"When I sold it, it was only with full disclosure of the modifications.'

I'm sure Ed is really at heart a fine man. He has a melodious voice and can sell stuff. Sorry though, I don't believe that statement.

On the other hand, when we were in the middle of the Covid supply issue crisis I bought a flat of old 2 3/4" low pressure Federal shells. I intended to use them in my French 1926 SxS...lots of barrel thickness, choked at .024, .024. I was tempted to try them in the Damascus Reilly but decided to wait. The issue is still not resolved in my mind and I've read the DBS lines and others. I'd still prefer to shoot 2 3/4" low pressure shells out of a 2 1/2" chambered gun than rechambering it.

Agreed, completely. And, it underscores the obvious ............. Ed cannot help but rehash old subjects that he is too lazy to do a search for.

It takes a gun out of proof and Stan is correct,and edd is fishing for something

Assuming the chamber walls are thick enough and the exterior of the barrels doesn't have some radical taper just ahead of the chambers, I'd have to agree with the thinking that lengthening would only serve to negate an explanation of Bell's testing results. Of course, one would want to explain the pressure limits of the gun if there were any. I plan on keeping my old Fox and telling the family it is a wall hanger out of fear they might move it to someone with even less knowledge than I have.

What Bell also pointed out in his "Finding Out For Myself" series is that simply lengthening the forcing cones will result in some pressure reduction. The only problem with that is--at least the last time I recall checking--the two British proofhouses don't agree on whether that renders the gun out of proof. (Lengthening the chambers definitely does.)

But as Argo points out, if you reload it's just not that difficult to make up loads--and not just target stuff but hunting loads as well--that are low enough pressure that there's no need to make any modifications to the barrels. That's especially true of 12s. Back when I was shooting 2 1/2" Brit 12's at pheasants quite frequently, I had a 1 1/8 oz load that was both very effective and with a significant safety cushion when it came to approaching any worries about danger due to pressure.

There’s a fine line between lengthening the forcing cones and lengthening the chambers. I’m not keen on removing metal where pressure is the highest.

I will not take metal out of the inside of any shotgun barrel. I don't care how short the chambers are, I can make shotgun shells that will work just fine. Sherman Bell's actual comment on long shells in short chambers is "The pressure rise in very small. Shoot shells that don't exceed the pressure range that is proper for the gun, regardless of the length of the shell." Using that thinking, I load and shoot 2 3/4" shells in 2 1/2" chambers when I feel like it, but load them to low pressure and reasonable shot charge. Right now, I'm way ahead in loading 2 1/2" shells, have plenty, so I don't worry about 2 3/4" shells. By the way, my 375 Ponsness Warren is a standard 2 3/4" loader with a sizing die that I made myself from a standard 2 3/4" die. That is the only modification and didn't cost me a cent. I probably paid about $65.00 for the loader 35 or 40 years ago.

I only reload CF rifle ammo- mainly 30-06, .35 Whelan, and the pre-WW2 M70 in .375 H&H, so I cannot speak informatively on the topic of shotgun shells. BUT, having a solid background in both machining and tool & die welding (TIG) let me state this--over the past 45 years, I have been fortunate to have owned and shot a fair number of good quality 12 gauge American mfg. double guns- I have never: (1) opened the chokes, (2) reamed out the barrels to remove defects, (3)lengthed the forcing cones or have screw in choke tubes installed- and, I never will. RWTF

interesting responses...

- certainly do understand and agree that collectors desire guns to be as original as possible, including chamber lengths...

- but what about hunting guns, that certainly will be fired?...popular wisdom says shooting 2 3/4 shells in guns chambered for shorter shells increases barrel pressure and recoil...that being the case, why not just lengthen all short chambered guns to 2 3/4? that way one will not have any issues finding factory loads...and old hunting guns will last longer...

as for the safety issue, i was trained to believe that so long as there is around .090 of metal left in front of the altered chambers, with no alteration to the forcing cones, then most old guns with fluid steel barrels, would be safe to shoot with light smokeless loads...interesting that the responses here that discuss guns with successfully altered chambers, do not mention any barrel wall thickness standards that were employed before the chamber alterations were completed...why is that?

No edd no!

Re the issue of how much metal is necessary in a shotgun barrel: There are various examples of 16ga barrels being fitted to 20ga receivers. The result: A gun that's lighter as a 16 than it is as a 20. And the reason that it's lighter is there's a larger bore surrounded by less steel in order to make them fit. But we don't seem to hear about those guns suffering catastrophic failures.

True, but they were probably pretty heavy 20s to start with. Each case is unique and has to be evaluated that way. ed is just stirring the pot. Again.

logic says, so long as there is sufficent metal in first foot or so of barrel, catastropic barrel failure should not occur...

fox 20 and 16 gauge guns were built on the same frame size...

o frame parkers came in 16 and 20 ga...

it would be educational if members here with any of those guns would post barrel wall thicknesses here...

re 16 ga fox...have three for sale at the moment, two philles and one utica gun...all three measure .090 in front of chambers...


once has a light 16 ga fox that measured .085 in front of chambers...new owner promised to shoot rst 7/8 ounce loads only...

this barrel wall thickness thing does not seem to apply to american made guns...but does seem to apply to some very light weight european guns...a particular french made gun comes to mind...customer wanted chambers opened to 2 3/4"...brought it to old ed for evaluation and alteration...he measured barrels in front of chambers and muttered..."not a good idea"...there may have been others, but i dont remember...i do remember him opening chambers on quite a few american made guns...

boy do i miss him...i feel like lee at gettysburg...handicapped without jackson and blind without stuart...

If you alter a chamber length it will be out of proof ,if a gun has multiple barrels and you lengthin the chambers it will be out of proof .buy a modern gun with modern steel proofed for modern ammo. a European 2.5 gun proofed for 1 1/8 oz cip loads is not proofed for 2 3/4 sammi ammo .no matter how much you beat the dead horse it's still dead

I think I remember measuring bores, chokes and such on one of those guns a long time ago. I don’t recommend it, but, I’d bet you can stuff a 20 gauge round in those bores, put a 12 in the chamber, fire it, and not hurt anything, save the two rounds.

It had very heavy barrels ,as I recall.

Best,
Ted

mc, please explain your criteria for defining a modern gun with modern steel barrels...

your statements are provocative but meaningless without details of pressure differences between 2 1/2 cip and 2 3/4 sammi spec loads...

and do you have evidence of many barrel failures of 2 1/2 guns altered to 2 3/4 guns...i do not...

also, a common practice of some who shoot vintage guns is to use light loads, usually about 10 percent less shot than standard load gun was designed to shoot, with velocity less than 1200 fps ...in an effort to reduce pressure to protect metal and to reduce recoil to protect wood...

this practice has been going on for some time by a lot of shooters, without reported problems...

and even better, rst built a very successful business creating black powder like pressure loads with smokeless powder...hopefully rst will resolve their componet supply issues soon and be back in business...

Any gun that has safely endured 100 years of any load available in a hardware store should be able to endure another shot. However, if you take a bunch of metal out of the inside of the bore, all bets are off.

No edd do some work yourself.

Ed is only bringing this up cause he has some English guns for sale for once.

doctor doom an his cohort black cloud...

And might be out of proof

Ha , that's quite an incomprehensible stretch.

mc: rigid british proof rules are not enforced here...

for example, safely opening chambers is forboden in the uk without reproofing...whereas, reproofing is optional here...and is rarely done...

we have been ignoring british proof rules for a couple of hundred years now, without diasterous consequences...

from a practical standpoint, whether a gun is in british proof or not is of little consequence here...

unless of course, one chooses to make it so, for reasons other than shooter safety...

an stan, ah jes cant be bothered wid you an yo negative sniping...

It's of great consequence to someone wanting a original in proof gun whether uk Spanish Belgian French you must be trying to hawk out of proof guns and looking for a pass from the academy .

The marketplace enforces the rules out of proof guns go begging

Back in the mid-70's, I bought a between the wars Sauer 16ga as a graduation present to myself when I completed my MA. It had short chambers. I had them lengthened, after which I fired hundreds of high brass pheasant loads through that gun. Back then, a lot of gunsmiths did it regularly. But back then, we didn't have very many gunsmiths--nor gun dealers--who specialized in classic doubles. Thanks to places like this, and to Double Gun Journal, pretty much anyone who has more than a passing interest in a classic sxs knows better now.

L., your post above is interesting and memory invoking...

alow me to remise and pontificate a bit...

-back in the mid-70's...while you were completing your MA, ?...i was workin in the suberbs of nyc, at a secure job, in order to provide for my family...

-at that time I was in my pump gun stage, specifically a 20 ga ithaca, with shortened barrel, don ja no...wonderful grouse gon hit was...prior to that, i had dallied with a 16 stevens, as that was awl i could afford at the time...eventually, i had the chokes cut off it, and then had rifle sites installed on the rib, making it into a slug gon for local deer hunting...that did not work out so well...

-as to your sauer, what wonderful gons they are...have had a few, with nary a problem nor complaint...surprised that after so many rounds of high base ammo, the stock did not crack...perhaps the chamber opening reduced the felt recoil, which helped protect the wood...

-and i am so happy that you and others have learned to not fire alotta high brass loads in old light weight guns...

as for chamber opening in general, the world loves to fill a vacuum...soon, 2 1/2" low base loads will return to us, eliminating the desire to alter chambers...eagerly awaiting that event...