I think you should look at how long your going to be able to seat bullets in a 7.62x39 mag then look at the throat depth length on your chamber. The best option may be to go single feed if you don't require a magazine.
My guess is if your going to the trouble of building a grendel bolt gun your going to want to wring every last bit of performance out of that cartridge which is usually limited by the AR platforms 60k ish limit, not to mention general accuracy issues generally associated with mag fed semi autos. I'm guessing your going to shoot for 120 grain vld type bullets which in my experience end up doing better in the caliber than the 140s. But that experience is based on an AR so you may find that you can throw 140s fast enough.
This will be a fun build to watch. I started off with a 20" Mid length grendel AR and killed a few deer with it using 125 nosler bt. One day I was playing with subsonic loads when all of a sudden I found one that cycled the rifle. Thoroughly excited, I pulled the trigger 3 more times and was rewarded with a nearly silent but functioning AR. I pulled the charging handle back on the jam and heard a slight hiss reminiscent of a PBR bring opened. At this point I realized that the rifle was working because none of the gas, nor bullets were leaving the barrel.
Long story short that barrel is now a 8.5" carbine length pistol that shoots Lehigh Defenses 95gr controlled chaos at 2400 fps and does a reliable 1.5 MOA @ 200 yds with a 2-A A 7x Leupold on top. It's a great cartridge and should be a real kitty on recoil if you go the bull barrel route. Barrel life should new excellent as well, I have a little over 3500 on my stainless AR barrel and it still looks/shoots great.
Sent from my A571VL using Tapatalk
Bookmarks