Old Marine, what's the length of your bolt & firing pin? The bolt should be 2.810" & the firing pin 3.278". There are some Grendel bolts out there that are 2.800" long which can cause excessive firing pin protrusion. Also there are "enhanced" firing pins that are supposed to be used in AR's chambered in 7.63x39 or 5.45x39. Those cases can have hard primers & need the longer tip on the enhanced firing pin for reliable primer ignition.
In the pic the enhanced firing pin is on the left...
In the pic the enhanced firing pin is on the left...
The trick is growing up without growing old. -- Casey Stengal