You may not need to be crimping at all, test for groups and see. Match shooters of single shots, in the 'old days' usually didnt crimp, and some of those groups havent been bested until recently. IIRC, many competition benchrest shooters dont crimp either.
The bullet can be crimped, if needed in a grease groove, no worries. I find that my cast bullets, if of the right dia. for the throat, have enough case neck tension so they dont fall out. It can be a bit more problematic with jacketed, but FL resizing should give plenty of neck tension for those.