I have a model 11 223 from around 2001. From new the gun had a tendency to crater primer pockets, even with lighter loads. This weekend I was doing some load development with H4895 and experienced the same issue.

My loads were:
Hornady 53 grain V-max
Lapua cases
24.1 - 26.3 grains of H4895
2980 fps - 3280 fps

I experienced some degree of cratering with all loads, however cratering seemed to remain constant at velocities of 3100 - 3280. I have read that cratering can be the result of a weak firing pin spring or too much firing pin hole clearance. Is this something I should worry about?