doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com 2.5" chambers and 2.75" shells

The flip side of the above is also true. If you reload 2 3/4" American hulls to appropriate pressures, you have no need to buy 2 1/2" shells. But why bother, since 2 1/2" factory shells are indeed available . . . assuming you have them on hand before you head to Bowbells, North Dakota for your next hunt--where I guarantee you won't find them at the local Wal-Mart (assuming there is one). So, in either case, you need to have appropriate ammo on hand, and you can do it either by buying 2 1/2" factory shells . . . or by making your own by using readily available 2 3/4" hulls.

The advantage of making your own: If you shoot your 2 1/2" gun very much--and I've put thousands of rounds through various 2 1/2" guns over the years--you will save enough money to buy yourself another 2 1/2" gun (or two). Reloading for the 12ga in particular, it's very easy to achieve low pressures, and it's very inexpensive.

Take your pick.

Thank you Larry. I assume that was the 2 1/2� chamber with a 7/16� forcing cone �British chamber�.

With over sixty seasons under my belt, I've yet to have to have to go to the local store to buy shells for my shotgun. My father did have to go to the local store(Lily, WI)to buy shells for a borrowed shotgun, sure enough they had 2 7/8" 10ga on the shelf but that was 1957.

I have read in the past & it was written by a "Qualified" Ballistician. There are numerous factors which all play an important role in determining pressures in a Rifle & all must be considered. In a shotgun, the pressure is built into the shell with few outside factors of much consequence.

The few caveats worth mentioning are;
1st As already stated the built-in pressure should definitely be compatible with the gun intended to be used with said shells.
2nd, the above statement about the pressure being built into the shell assumes the crimp is free to open. Two things which can affect this are the "Loaded" shell enters the cone which restricts the opening of the crimp. This is a strog possibility if loading a roll crimp true 2 3/4" case in a 2�" chamber. As already mentioned a stepped chamber rather than a cone is also a No-No. I have always relied on my own judgment rather than going to a "Qualified" Gunsmith but its hard for me to imagine anyone with enough knowledge to make a decision about using the longer hull who would not check out the cone. A quick glance into the breech will show that step as opposed to a cone.