Unless the gun is some sort of super rare specimen or something I plan to "flip", I generally send barrels off to Briley if I plan to use it. I have them lengthen FC and "tweek" chokes consistent with my expected use. As suggested above, that work enables me to shoot an occaisional 3" 20ga in a M21, but I don't make it a pratice to shoot modern hot stuff in an older 2 1/2" gun.

A Springer Spaniel, a 6# double and a fair day to hunt.