Whenever I size a pad, I mount the pad onto the gun and mark it around the bottom with a regular #2 pencil. Then I use my Ryobi vertical belt sander to sand it down. I keep turning it over to see where I need to sand. The pencil mark won't rub off while I'm doing this. I tried using a scribe once so I could fill it in with chalk and it caused the wood at the very end of the stock to round off all the way around the gun, because I pressed too hard against the stock. Uh-oh. With a sharp tool, you take the risk of cutting the end of the stock, too. So, I just went back to using the pencil. If it does rub off, which it usually doesn't, I just put it back on the stock and remark it. I use a sliding t-bevel square to copy the angle of the toe and I set my sander deck to the same angle and it comes out exact. When I get it close, I put it back on the stock and sand it with fine sandpaper on a block until I get it perfect. If I have to sand close to the stock, I'll remove it, maybe several times until it is exact. Works for me.
