Gunsmithing Stupid question - firing pin size?

[XTREM HTR16]

Looking at replacing a couple of J-locks and noticed PTG has different firing pin sizes. Is it based on bolt face size or primer size, ie the .062 firing pin would be for small rifle primers and the .075 would be for large and magnum?

 

[Aeon1]

A standard pin is ~.075" in a factory bolt regardless of chambering. The .062" would be used for a PTG bolt with the small pin option or if you had a bushing installed for a small pin your factory bolt.

 

[XTREM HTR16]

Thanks. .075 is the one for me then!