I do them all on the stock with a 6 X 48 belt sander. Final fitting is by hand. It's just a matter of going slow and watching the angles. Here is a little kink I discovered several years ago that works well. I buy some metal foil faced tape that is used for weather proofing. It comes in a roll from the local Ace store. The last I got was about 3" wide and not more than a few thou. thick. If applied to the stock it will allow you to get very close and it will tell you when you are getting there. One word of caution, this stuff is extremely sticky. I never leave it on more than a few minutes for final hand fitting of the pad. I assume, if left on for long, it would be very hard to get it back off. Best Regards, Jack