05-05-2019, 12:04 AM
LRRPF52 Wrote:If you're using a bolt with the mass of the LR-308 and CMMG Anvil bolt, you will depart from the 3:1 rule of carrier mass-to-bolt mass if reduce the carrier weight.
That can/will result in sluggish unlocking unless you gas it hard, and you still run into the issue of sluggish cyclic rate in the initial rearward inertia.
This is one of the problems with the Remington Model 740 and 7400 semi-auto hunting rifles.
The CMMG Anvil in Grendel also has a bit more mass than even a .308 bolt because of the reduced bolt face width for a narrower cartridge.
Compound that with the fact that you have 10gr less of case capacity and lower working pressure than .308 Win., and you are really setting up for needing to make some gas system changes if you want to have a reliable action.
I think for a 6mm AR, the CMMG Anvil makes a lot of sense where you aren't worried about bolt thrust, since the 6mm AR has more bolt thrust than 6.5 Grendel due to the bottle neck effect on back pressure.
Never knew they had a 3:1 bcg weight ratio to bolt.
But how does that work because wouldn't a lowmass bcg in a ar15 be below the weight ratio as well. And suffer from the same gas issue you were speaking of.
I may put that as a side project for later this summer. If I can't get my other projects sorted. I might buy a cmmg jerk the bolt and mill the bolt body down to fit a ar15 lowmass bcg I have laying around and then mess with getting the barrel to fit a ar15 upper, probably gave to mill the extention down a few thousands.
I like too test stuff lol are break stuff lol maybe both lol.