Well, this is sounding more confusing all the time. And, even if I were to come up with an accurate method, I'm still not sure of the data. Example, my 16 ga. Trojan was made in 1921. Probably chambered for 2-9/16", right? So, is that what the chamber would measure? Or, is the chamber longer, to allow for the opening of the shell? And, of course, there's only 3/16" between that, and 2-3/4".

Last edited by kstt; 11/06/06 12:02 PM.