I know there are people out there making firing pins for both and they try and harden them with a torch, you cannot properly harden them this way. It takes quite while in an oven for the firing pin to reach 1500 deg. F evenly, then it is quenched in a sulpher based oil, polished to remove scale and shiny, then back in the oven until it reaches a straw color then quench again.
I have made many dozen hammer gun firing pins and have never hardened any and have had only a few reported that have broken. These were made out of 01 tool steel or oil hardened drill rod. Now I have switched over to S7 which is a shock resistant tool steel.