I was reloading that caliber last fall for my Mini-14. Some I crimped and others I did not. I did not see much differance in performance. You can get a factory crimp die from LEE where you don`t have to worry about the exact case lenght consistancy for roll crimping in a seating die. Yes if you crimp the bullet case too much and the crimp is not uniform you will loose accuracy as stated. I don`t think setback is a problem for us plinkers anyway
