I have a set of RCBS 32 Long/32 H&R carbide dies and the die that does the expanding/flaring of the case mouth has an expander that mic's at .311." At first thought that doesn't seem too bad but I have a couple of 32 H&R's and one requires boolits sized to .312," and when loaded using this die the crimp and neck tension are definitely too little. As a result I'd like to turn it down to .310" or .309." I've read before that it's extremely easy but I've never done it before. What do you do, just chuck it in your drill press and use a mill file on the case expander part before the section where it flares the case mouth? Or do you use something lighter like emery cloth? Any info would be greatly appreciated. I didn't see much about doing this on the web.