Grendel and .473 bolt face

[Tedward]

Even is you modify the surface on any bolt, whether you machine a 7.62 bolt deeper or open up and deepen a .556, you are removing the surface hardening. I have been talking to the bolt manufacture guy, M.F., and when a bolt is hardened, it is to the surface, not throughout. Then it is shot peened to harden the surface further. He explained it is like taking a million tiny tiny ball peen hammers and hitting the hardened surface to creat smashed hardened surface. SO, if you alter the surface in any way, you are removing the material hardened surface and you weaken the bolt.

Don't mess with them, buy the correctly manufactured and finished product. OR risk you safety.