The dremel works perfect with the sanding drum, I usually trim it down flush with the top of the hammer extension if that's enough. I put the rifle in a cleaning stand, then lay a newspaper over the frame and force the hammer thru the paper, then use masking tape to seal the torn paper against the hammer, this keeps metal dust out of the frame. When you're all done, touch the hammer up with blueing, I use a Birchwood Casey touch-up pen, let it work for a minute, then neutralize with gun oil.
Tim