I'm trying to use my dremel to get rid of the first tooth and part of the second one for the sorbo pad I'm adding, but my dremel can't do anything to my piston, just little scratches. What do you guys do for your metal pistons to remove the teeth. Do I need to get a different tool, or a new dremel head if so which one is ideal? Thanks ahead of time. Oh and on a side note, how much do airsoft techs charge people for doing a full blown custom job on a gun?