A pretty sweet "G"

[myrifle]

I seem to always mention this but Brownell’s is one of the few companies to have a different overall length with their 6.5 Grendel bolt. Bill Alexander used the deeper .136” bolt face compared to the 5.56/223 .125” bolt face depth. AA lengthened the 6.5 Grendel bolt .01 to a overall length of 2.810”. The Brownell’s bolt measure 2.800” with a usual tolerance of + or - .002-.003”.

I would not switch firing pins between different AR-15 bolts without first measuring the firing pins. The specification for firing pin protrusion is minimum .028” maximum .036”. The maximum AR-15 firing pin length is 3.279” with a tolerance of -.009”. Excessive firing pin protrusion can contribute to pierced primers or failure to fire with a short firing pin. Forum members have measured Brownell’s firing pins and most measure 3.269” + or - .002”.

This problem became evident when Odin Works released their 6.5 Grendel and people were getting pierced primers. The problem was 2.800” length bolt with standard AR-15 length firing pins and out of spec firing pin protrusion. Toolcraft released 2.800” length bolts for a short time but switched to 2.810” bolts. Brownell’s list a shorter AR-15 firing pin on their web site but I’ve never seen them in stock. I called Brownell’s technical a couple years ago and they were unaware of the issue. I have never read where Brownell’s has started using the longer 2.8100” bolt.

As a safety concern I try not to get my AR-15 firing pins mixed up. Excessive firing pin protrusion can contribute to a slam fire with an AR-15 when chambering a cartridge.

As long as you use the correct length firing pin the Brownell’s bolt/BCG in 6.5 Grendel seem fine. I just wish all the 6.5 Grendel bolts were 2.810” length so their would be less confusion. Any time you use a different caliber in the AR-15 than 5.56/223 there isn’t as much standardization.

Thanks for reminding us. I had totally forgot about that.