So I usually just use a lee trimmer on all my stuff, chuck it up in my drill, and it makes short work of all my brass. The only problem comes with the .458 lott. To be trimmed, it has to be expanded first. And expansion... shortens brass, so it doesn't even matter, too short to trim. Well I was gettin a little annoyed with brass of slightly different lengths and my inability to trim them.
Cue RCBS trim die. Just got one of these from midway and it works very well. Takes care of sizing and your trim in one step. Very hard. As I can tell using the file didn't make one mark on top of the die. You definitely have to do some chamfer work to get your brass clean. Maybe one of these days I'll get around to filing down the guide to my lee trimmer so it'll fit into un-expanded brass, but this guy will do the trick until then.
Oh and I would only recommend you use this thing in a rock solid single stage (I usually load with a lee classic cast o-press) Cause you are filing with some force on top.
