Mr Brown,
I have a 20 and 12 repro for several years and have never thought of looking at the forcing cones. I just shoot them, break clays or drop birds and move on. Oh and clean them from time to time.

Though I can not answer you question, I wish you best of luck in your quest.

Going for dove again tomorrow.


NRA Patron, TSRA, Whittington Center, DWWC,DRSS
Reloading Ballistics App at http://www.xplat.net/