Which Bolt?

[Keep The Change]

Is there any sort of consensus pooling up behind certain manufacturers of quality 6.5 Grendel bolts?

[LRRPF52]

The AA bolts are the ones to beat. The RDT&E AA has done on their bolts exceeds what most companies even do with 5.56.

AA really did most of the groundwork for a strong and reliable bolt and extractor with the 50 Beowulf before the 6.5 Grendel even existed.

The foundation for the engineering and design of the bolt was built on the lessons learned from the Colt 7.62x39 Sporter, which was done in the 1980's, and there are a lot of things with the 6.5 Grendel bolt that are different than a 5.56 bolt in order to optimize extractor geometry around the thicker case rim, extractor lip material, pin location, the alloy used, firing pin protrusion and compatibility with regular AR15 firing pins, extractor lift travel, and ejector dimensions.

What I have seen in the after market is a very slow learning process trying to catch up, and usually failing when looking at long-term batch-to-batch consistency in the metallurgy and sourcing of quality extractors. The initial attempts to make .124" bolt face depth "7.62x39" bolts work usually failed, and the cartridge started to get a bad name for this, even though you didn't see it with the AA bolts.

[Keep The Change]

Thanks LRRPF52,
I knew a lot of the history with Bill Alexander and his development and figured his knowledge and R&D would have his bolts at the top. So I expected to see AA bolts in the short list.

[82HALO]

LRRPF52, what are you thoughts on the JP enhanced bolts? Slowly getting parts and was curious about options.

[am4966]

Jp makes good stuff, period.

[LRRPF52]

LRRPF52, what are you thoughts on the JP enhanced bolts? Slowly getting parts and was curious about options.

I've always had good experiences with JP products, but I just don't have any personal ones with their 6.5 Grendel bolts.

There are others on the forum who have and do with much success. I've been trying to get a definitive answer on what bolt face depth the JP bolts use, as well as the length of the bolt.

[Joseph5]

Maxim bolts are good and I believe they make the bolts for Precision Firearms or you can get them straight from Maxim.

[LR1955]

The AA bolts are the ones to beat. The RDT&E AA has done on their bolts exceeds what most companies even do with 5.56.

AA really did most of the groundwork for a strong and reliable bolt and extractor with the 50 Beowulf before the 6.5 Grendel even existed.

The foundation for the engineering and design of the bolt was built on the lessons learned from the Colt 7.62x39 Sporter, which was done in the 1980's, and there are a lot of things with the 6.5 Grendel bolt that are different than a 5.56 bolt in order to optimize extractor geometry around the thicker case rim, extractor lip material, pin location, the alloy used, firing pin protrusion and compatibility with regular AR15 firing pins, extractor lift travel, and ejector dimensions.

What I have seen in the after market is a very slow learning process trying to catch up, and usually failing when looking at long-term batch-to-batch consistency in the metallurgy and sourcing of quality extractors. The initial attempts to make .124" bolt face depth "7.62x39" bolts work usually failed, and the cartridge started to get a bad name for this, even though you didn't see it with the AA bolts.

LRRP52:

We sheared bolt lugs with the AA bolts when the Grendel was relatively new. Since I used both, and sheared lugs on both, my estimate was that the Colt 7.62 X 39 bolt worked as good as the AA Grendel bolts. Yes, I sheared lugs on each one of those, too.

Certainly, the cheap 7.62 X 39 bolts sheared lugs faster. I even used a 5.56 Bolt that was reamed out with work done on the extractor so it would take the Grendel. Although I never would have figured, it lasted longer than any of the 7.62 X 39 bolts. It equaled the Grendel bolts of the time. Yes, it too sheared a lug after about 4K rounds.

I do have a JP race gun Grendel upper whose bolt has probably lasted longer than any other Grendel bolt I have used. Great upper, really fun to shoot. Best balance for standing positions than any other rifle I own.

LR55

[LRRPF52]

I was talking with the military sales guy from Daniel Defense at SHOT, who retired from a career in Ranger Regiment and the AMU.

I was surprised to hear him say that they were breaking bolts on the 7.62 NATO M110 left and right, because the AR10/SR25/M110 bolts are massive.

http://www.m4carbine.net/showthread.php?137240-Special-Forces-Worry-About-M110-Durability