I've tried every method known to man, and I've wrecked some stocks in my day. The first recoil pad I ever fitted for a client was on a Galef that was considered a family heirloom and I nicked the stock. Fellow got custom stock job and still wasn't exactly happy.
My opinions-
YES belt sander, faster/wider=better
YES large 10"-12" disc sander bigger=better
NO grinder
NO drum sander even the big 14"ers
NO Surform tool
NO auto body air equipment (DA, reciprocal, orbital, rotary etc)
NO hand-sanding except polish or touchup of lines, NO shaping
NO files or rasps
If it's smoking you're doing something wrong
Here's what I use.... it's made by B&R, from Brownell's
http://www.brownells.com/gunsmith-t...ols/b-r-recoil-pad-fitting-jig-prod44670.aspx
I'm not arguing, these are just my opinions based on my experience. IMO, buy the jig and then do a few for your buddies and it's paid for....
And if you have a large table saw this guy is also an option....but MUCH harder to use,
http://www.brownells.com/gunsmith-t...ools/universal-fitting-fixture-prod25267.aspx
you will get some in your eye.
And you'd best be limber and have good eyes and hands.
I laid a table saw over on it's side....
hth
al