08-07-2022, 05:43 PM
MISportsman Wrote:On the other hand, isn't the grendel and the x39 the same identical case just different neck size?
It is a little more complicated than that. The 6.5 Grendel is based on the 6mm PPC case with the shoulder blown foreword. When compared to the 7.62x39, the rim and base diameters are the same, but the PPC and Grendel have less taper and the shoulder and neck are very different. It is possible to turn 7.62x39 brass into Grendel, but it requires fire-forming to blow out the shoulders and body.
There is actually a reason that the developers of the 6.5 Grendel decided to use a deeper bolt face than the 5.56 NATO. The rim of the Grendel (and 6mm PPC, 6mm ARC and 7.62x39) is thicker than the 5.56 NATO. The bolt is a little deeper to adapt to the thicker rim and make the extractor stronger. Even with the deeper bolts, extractors are the weak link of the Grendel, so pick up an extra one, just in case.