I'll keep it short, but the only experience I have with firelapping a .22lr involved using Verl Smith's (LBT) abrasive compound on my 10/22. According to instructions, I was supposed to put "a dollop" of compount on the tip of the bullet, then chamber and fire. I kept this up while cleaning and shooting for group. The group never improved and I realized that I had fired more rounds than I originally had planned. I took a peek down the bore and found about have of the rifling profile was GONE. Fortunately I'll never shoot out the rest of the bore with .22lr, but I still feel stupid every time I remember that dumb little adventure I took.
I've also firelapped centerfire revolvers and I feel that it does work quite well. I'd never try it on a .22lr again though.
To the original poster, PLEASE don't screw up nice little 39A.
