doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com 2 3/4" shells in a 2 5/8" 16 gauge

I heard there was a sale going on at Cabela's on Kent bismuth shells and I happen to live about 10 miles from one so I stopped over there when I was going past it. Without thinking, I purchased a number of boxes of the 2 3/4" shells for my 16s and on the way home I realized my 16s were 2 1/2" and 2 5/8" chambers. We have discussed on this forum in the past the use of 2 3/4" shells in a 2 1/2" chamber but what are your thoughts on their use in a 2 5/8" chamber? Since they have a no return policy on ammunition I may be selling the 6 boxes of 10 shells each I purchased.

My opinion is they are perfectly safe to shoot in a 2 5/8" chamber. Fire a couple and if the mouth of the hull isn't jagged or torn you're good to go.

MANY times it is stated that is is "safe" to do so, but my personal opinion is don't do it. ( and I am the most frugal person I know - second to my Dad). Seriously for a few bucks here and there why ? But I also wouldn't feed a good dog the cheapest dog food or put 87 octane gasoline into a performance engine.

Mark, what is there a realistic danger of? In this case the maximum difference in hull length is 1/8". The forcing cone itself is at least several times longer than this. Also, very few hulls are actually full published length. Seriously, what am I missing?

If they're American factory loads, it's possible that the service pressure of those loads will exceed the service pressure the gun was designed to handle. The extra length of the hull in a shorter chamber will also result in another increase in pressure. Most likely a few hundred psi, but possibly a bit over 1,000--per Sherman Bell's tests, reported in DGJ.

I have done it, and many people here do. But you need to have a clear understanding of the above issues, and you have to take steps to reduce the pressure of your reloads. I probably wouldn't bother if I were only shooting a few boxes per year. If you're using the gun a lot for targets, then working up low pressure reloads--probably 8,500 psi or less, which is 3,000 psi under the standard service pressure of American 16ga loads--should keep you safe. Assuming, of course, that you're starting with a gun that's safe even with factory short shells.

You should also consider the gun you're shooting. If we're talking something like a Fox or Parker with short chambers, that's a different story than a 2 1/2" British game gun. American guns in general are more likely to be overbuilt than Brit game guns. Thicker barrel walls, etc. When you think of the number of those that have had their original short chambers punched to 2 3/4" and have been digesting factory loads--sometimes pretty heavy ones--for 70 years or more, that may give you more comfort in shooting low pressure reloads in 2 3/4" hulls. My first 16ga was a pre-WWII Sauer with short chambers. Not knowing better at the time, I had those lengthened to 2 3/4". After which I shot the gun for 20+ years, often using 1 1/8 oz "Express" loads on pheasants. The only damage the gun ever suffered was a break in the linkage between the top lever and the Greener crossbolt. But then Sauers, and German guns in general, are also on the stout side.

In any case, it's something you should not do without very careful consideration of the specific gun and the uses you have in mind for it.

I wouldn't make it a habit, but I think a few wouldn't cause a problem. I'd be more concerned that the load might be excessive then the extra length of a shell.

PS. No doubt many many 2 3/4" shells were fired in that gun in its lifetime.

2 1/2 16ga shells are easy to get, are sweet to shoot and real bird killers. You wouldn't be fooling with an old gun like that if you didn't love it. Go 2 1/2

My point is shotgun chambers have no relationship to a rifle chamber where several dimensions are critical in cutting chambers. With shotguns it seems that "well, it's close enough" was and is the most common attitude. No one ever thought a few thousandths made any difference.

Tom -- what kind of gun is it? Stoutness of barrels is a bigger factor than chamber length. I wouldn't be too worried unless we're talking thin, European, ancient etc.

Joe- I do not suggest any imminent danger but I still say "why not care to do it right?" What you "can do" isn't always the best course of action. Longer shells in short chambers can and most likely will raise pressures. Is that an insignificant <5% or a more concerning 10% on a max waterfowl load? I don't think either of us can say for sure in a specific speculated gun/ load combo.
Now to te original poster 60 rounds for a few years of waterfowl hunting? I wouldn't rush to get rid of the "dangerous loads." But 60 rounds as a gateway to not caring and shooting anything, just not how I would do it.