Firing pin

[hifiwasabi]

I’m gathering parts to build my MRA and I’m wondering if I need a specific firing pin for 6.5 Grendel, or will any 5.56 or 7.62x39 pin do?

 

[dusticles]

I'm in the process of building a 6mm ARC so reading a lot about Grendel. Grendel was built on a rifle meant for 556, only changed the bolt and barrel. Firing pin is the same