I agree. The danger is in loading a shell who's uncrimped length is too long for the chamber. Roll crimped shells will be longer than folded crimped shells even though they both started out at the same length before being crimped. If the crimp unfolds or unrolls, as the case may be, into the cone, it will cause a constricted area and pressure will spike. I used to hunt deer in Iowa with a man who one day inadvertently grabbed a handful of 3" slug loads and fired them in his 2 3/4" gun. He got away with it, without ill effects, but it's certainly not a practice to be recommended. Also, I agree that smokeless loads should never be fired in a black powder proofed gun, Damascus barreled or otherwise. When I measured my chambers with a proper tool I learned that they were indeed too short for a 2 3/4" shell. They are in fact 2 5/8". Though I could probably cut off and skive, and then load 2 1/2" black powder shells for this gun I have no need, desire, or intention of doing so, and never did. Ever!
