I just watched Larry Potterfield remove the charging hump from a LR mauser action. It was on the guntech section during American Rifleman TV. He used a Dremel with one of the coarse sanding drums and a mill followed by an India stone. I think he was doing okay until he got to the stoning...looks like to me he rolled the edges over way too far. It wasn't near as sharp and clean as the ones I've seen many of the members here do. I did see one thing that I thought was kinda neat, he laid a piece of sand paper smooth side down over the bridge, and lapped the rear base to the profile of the newly contoured bridge. I've almost finished mine, but I started with a 9/16 HSS end mill, then a , then the stone. I'm trying to get a nice clean line along the sides of the receiver like the ones Z1r and others have done. Have any of you guys ever lapped the rear base? I noticed you can see light under my rear base, but i figured I would continue stoning the bridge until the lines were nice and crisp and the base fit down tight. He also checked the tops of the bases with a level, and lapped the rear base until it was level with the front. Honestly this is something I completely neglected to check, but i will now.