Primers- How Interchangeable are they?

[VASCAR2]

In AR-15’s I like to use thicker primer cups like used in the CCI 450, CCI 41, Federal Match AR and Bench rest primers like Remington 7 1/2. I have loaded some 223 ammo with standard primers that were starting to pierce even though not loaded hot. The AR-15 uses a floating firing pin and there is .008” tolerance in firing pin protrusion. The thicker primer cups add a margin of safety against slam fires or bolt depth and firing pins that might be on the long side of spec.


I always try to keep my AR-15 firing pins with the bolt and carrier where I know they are in spec.