Thread: what steel and what hardness for a 22lr firing pin

Rambo, I have never come across one of this make in 45+ years of gunsmithing! It looks very much like a copy of the Marlin Model 57 .22. Hopefully there is enough of the broken pin to make a good copy. My only comments would be to make sure there are no right angled corners on the replacement pin. They should all be radiused to avoid stress cracking in the corners. The nose of the flat firing pin should be tapered at the contact area with the rim of the cartridge until is is about 1mm wide and the edges lightly radiused to ensure positive ignition. I assume it is a hammer-fired system and I would suggest that the back 1/4" of the pin is only drawn back to brown colour to make a harder surface for the hammer to strike. This will prevent the back of the pin from 'mushrooming' from extended use.