12-05-2015, 04:52 PM
Welcome. It would have to be matched to a barrel that was chambered with the headspace set up for a .124" bolt face depth.
The 6.5 Grendel and Les Baer .264 LBC-AR chambers use a .136" bolt face depth. AA supported the different vendors who wanted to make Grendel barrels by supplying them with AA .136" bolt face depth bolts.
Some other vendors figured they could use .124" face depth, and the chambers are cut accordingly.
The biggest challenge with a .124" face depth is the extractor lip geometry. Since the Grendel brass rim is much thicker than 5.56, it makes sense to have more material on the extractor lip. In order to do that and have enough clearance for the extractor groove, you have to go backwards, which locates the bolt face deeper.
The strongest 7.62x39 bolts on the market are made by LMT, using one of the AerMet alloys. They have a .124" bolt face since every 7.62x39 barrel maker out there uses that design, being unaware of the R&D Colt did on the original 7.62x39 Sporter. The extractors still fail on the LMT bolts, because there just isn't enough material there.
The 6.5 Grendel and Les Baer .264 LBC-AR chambers use a .136" bolt face depth. AA supported the different vendors who wanted to make Grendel barrels by supplying them with AA .136" bolt face depth bolts.
Some other vendors figured they could use .124" face depth, and the chambers are cut accordingly.
The biggest challenge with a .124" face depth is the extractor lip geometry. Since the Grendel brass rim is much thicker than 5.56, it makes sense to have more material on the extractor lip. In order to do that and have enough clearance for the extractor groove, you have to go backwards, which locates the bolt face deeper.
The strongest 7.62x39 bolts on the market are made by LMT, using one of the AerMet alloys. They have a .124" bolt face since every 7.62x39 barrel maker out there uses that design, being unaware of the R&D Colt did on the original 7.62x39 Sporter. The extractors still fail on the LMT bolts, because there just isn't enough material there.
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