doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Nitro Proof Damascus 2-1/2 inch

My opinion is not better than other's, but .090" at the end of the chamber is the lower limit, for me, for damascus. No concern with 4140.
We know using long for short chamber shells will raise the pressure an average of 700 psi. Bell's study is 1/2 way down here, and note we have NO modern data regarding 16g and 20g
https://docs.google.com/document/d/1ZIo0y746UsSRZIgRuuxwAbZjSBHitO_EanvwLYc-kGA/edit

And max. pressures are at 1-2" with today's powders.



SO I would not use a 2 3/4" shell in this gun.

That said, B&P Comp One 7/8 oz. is only 5,800 psi, and some nominal 2 3/4" 12g shells measure shorter after firing. Things obvious change, but I've done some dumpster diving at the club and measured a bunch of empties.