I'm loading for the 400 cor bon. I've shot 100rds of my handloads so for and accuracy has not been so great. I've gone back to look at whats happening in my loading steps. Information calls for a tight crimp to prevent setback and a good flare to prevent shoulder from collasping while seating bullet. It seems I've been over doing both and destorting the bullets. Lee calls for 1/2 turn + after crimp die touches shellholder for minimum crimp. I've been going more like 3/4 turn and pulled bullets to find way too much damage done to the bullet while roll crimping. I've also been flaring too much which instead of helping seat the bullet, actually gives the neck a V shape and crushes the hollowpoint while seating. Just loaded 50 more and everthing went smoothly. Maybe they'll shoot straighter.