02-05-2016, 11:05 PM
Welcome aboard. My recommendation is to avoid the "7.62x39" bolts that use a .125" bolt face depth. Reason is extractors are more prone to breakage, even with the top end bolts.
Colt did their engineering, RDT&E on the 7.62x39 project, and found that they needed to move the bolt face back to get an extractor groove that would accommodate the thicker rim of the Russian cartridge. They used a .131" face depth.
The Grendel uses a .136" face depth. I don't know why people are still trying to make the .125" bolts work, because you will run into a dead end every time with the extractor geometry.
It is good to see that they are using the SAAMI chamber, but I would get some extra extractors if you can if you plan on getting that barrel. By the time you pay for 2 extra's, you're into better barrel pricing.
Since it doesn't say what the other BCG is using for a bolt, I can't be sure.
Colt did their engineering, RDT&E on the 7.62x39 project, and found that they needed to move the bolt face back to get an extractor groove that would accommodate the thicker rim of the Russian cartridge. They used a .131" face depth.
The Grendel uses a .136" face depth. I don't know why people are still trying to make the .125" bolts work, because you will run into a dead end every time with the extractor geometry.
It is good to see that they are using the SAAMI chamber, but I would get some extra extractors if you can if you plan on getting that barrel. By the time you pay for 2 extra's, you're into better barrel pricing.
Since it doesn't say what the other BCG is using for a bolt, I can't be sure.
NRA Basic, Pistol, Rifle, Shotgun, RSO
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
www.AR15buildbox.com
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
www.AR15buildbox.com