Shell trimming is very easy to do. Some use an exacto knife and a dowell with a mark that is 2 1/2" above the hull base when inserted inot the hull. Cut to the mark as you turn the shell around the dowell. Works well for just a few hulls.
I have a home made rig that trims shell as fast as you turn them. Easy to do a case in an hour.
Another trick is to put a cutoff blade/disc from a dremel tool in a drill press. Set the table 2 1/2" from the edge of the disc and rotate the hull as the disc trims the end.
All systems cost less than $10.00 to make or use. just pick the right one and go to work. By the way Federal Papers trim very well and look perfect in any double. Old style AAs can be used and this is a good way to get rid of some with cracked mouths. They often trim back to perfect hulls.
