Rounding the strike end of the firing pin may be help full. I noticed some firing pins are rounded a bit to start with. I believe finding the right combination of bolt, firing pin and trigger group may have effect on how well the firing pin holds up. The firing pin being struck squarely I believe would drive it straight to the primer with out banging it around in the firing pin channel. AR-15 firing pins are rounded on the strike end and are nearly resting on the primer with the bolt closed so when the hammer strikes there's very little travel. Unlike 9mm firing pins that work by inertia and have a ways to travel before striking the primer.