I used to crimp all my ammo, both rifle and pistol. I no longer crimp bottle neck rifle, whether in my bolt action or AR’s. Ever since I started turning case necks and separate body sizing followed by neck sizing with the Lee Collet Neck Sizing die I get plenty of hold with no setback and more consistent accuracy. I initially loaded up dummy rounds and ran them through my actions many many times and measured them every time with no difference.