07-02-2019, 11:26 PM
OK the diameter of a Grendel bolt is the same as the 7.62/39 or AK round. It is quite a bit larger than the 223/556 bolt. Even though they are physically the same size on outward dimensions. The difference in the Grendel bolts has to do with the depth of the face of the bolt. The AK round used a .124" depth as do some Grendel's this at one time was called Type 1 the true Grendel bolt is deeper and it measures about .136" and earlier was known as a type 2. You really need to know what your barrel is supposed to use and use the proper bolt