Crimping is not going to help if there is no neck tension. Screw your sizing die down another quarter turn, then check with the seating die to see if there is enough neck tension. If not go down another quarter turn. Sometimes you have to realy cam over a press to get the proper sizing for FL sizing. If it is nekc sizing, do go down another quarter turn at a time, and hold the ram with pressure for a few seconds, some brass is more springy than others, even out of the same box of ammo at times.
No matter how many times you do it and nothing happens it only takes something going wrong one time to kill you.