So I made my firing pin look more like the photo on the right and it helped a lot with the cratering but didn't stop it entirely. I then made the firing pin a little more blunt but it failed to ignite the primers. I put it back more to what it is on the left and it fires okay but the cratering returned?
I also get really erratic velocities with this rifle (ES of 50 - 100fps is not uncommon). I've tried about everything I can think of but nothing works.
I then reviewed a diagram of the bolt assembly and noticed I had forgot to install a small ring between the firing pin spring and the bolt retainer spring. The spring has been missing for over a year but luckily I found it under my reloading bench and reinstalled it. I haven't had chance to shoot it since.
My question is: do you think the elimination of this little ring could be why my ES is so high?