I have a new-to-me original '87 in 12 gauge. It has a 32" full choked barrel, and I shall leave it that way, naturally. I've heard that these guns have a 2 5/8" chamber, and like 2 1/2" AMMO. I took a brand new never fired plastic shell case 2 3/4" long, and it loaded into the chamber without interference of a short chamber. I measured the chamber with my home-made chamber feeler, and it comes out at 2 3/4".
What gives? If I shoot 2 3/4" ammo, I cannot see how it should be a problem. I also have 2 1/2" brass cases, and of course, they load and cycle perfectly...no hang ups at all. If I shoot ammo cut to 2 1/2" in a chamber that is 2 3/4" long, is there an issue with pressure, safety, or pattern damage? I will only shoot black powder in the old girl.