Life Usage of Bolts and Extractors?

[PeteDavis]

I wonder what the expected lifespan (in terms of rounds) is of a Grendel bolt and extractor in an AA production rifle?

I assume it makes sense to have a spare for each, with each weapon.

Also, how difficult is it to replace an extractor?

Pete Davis

[Klem]

Pete,

I imagine it depends on how hot your rounds are and how brutal your system is. Hot rounds hammer the bolt and early unlocking puts a lot of strain on extractors. If you don't mind 50fps your AA Hard-Use bolt should last the life of the gun (10-30K rds)

If you carry a spare bolt in the buttstock you will more than likely never need it.

[A5BLASTER]

From my own testing with some AA barrels.

Tune the gas system and lapp the reciver face and the bolt should last longer then the barrel does.

Changing an extractor is simple, press down on it where the pin goes through it and with your other hand use something to push the pin out and then install the new one.

I have a bolt in my 12 inch grendel that went through 4 16 inch fluted AA barrels and it and it's extractor is still going strong. All 4 of those barrels were run with wolf fmj and my 120 gold dot handloads till they died.

The round count is so high I still can't believe how how it is and the bolt is still going.

[biodsl]

What about gas rings? I think I need to do a better job lubing the inside of the carrier. I have two bolts that won't support the weight of the carrier when stood vertically on the bolt face.

[A5BLASTER]

What about gas rings? I think I need to do a better job lubing the inside of the carrier. I have two bolts that won't support the weight of the carrier when stood vertically on the bolt face.

Yea I did change the gas rings a couple of times. I forget how it's said to test them to see if they are still good. But I do know I have and do have new gas rings on new bolts that won't support the weight of the bcg.

I have been getting the one peice gas rings off joebobs website.

[LRRPF52]

Depends on:

Gas system length/barrel length
Gas port diameter
Loads used
Round count compressed in short time or spread out over long time
Suppressed without gas choking
Bolt alloy, processes, and QC

I've personally broken bolts on 5.56 CLGS blasters running very tortuous high volume sessions, but the bolts broke after 10,000 rounds of that. Had those bolts been made by Diameco in Canada or LMT enhanced, I doubt it would have happened.

I was going through all my Grendel brass recently and forgot how much of it I have. I let my wife pack up a lot of the boxes of it and she informed me I don't need to be buying any reloading components anymore.

Given the weight and volume of boxes full of Grendel brass, and the fact that a lot of it is into multiple firings (I found a ton of Lapua brass), I can only guesstimate how many thousands of rounds of Grendel I have fired through my various 6.5 Grendel AR15s.

As soon as I break something, I'll let everyone know.

Most of my Grendel shooting will be suppressed looking into the future, which can be harder on bolts if you don't manage the gas system well.

I'm using Bootleg carriers to choke the gas down to the most restrictive setting on them when shooting suppressed.

[Lastrites]

What about gas rings? I think I need to do a better job lubing the inside of the carrier. I have two bolts that won't support the weight of the carrier when stood vertically on the bolt face.

That's not how the manual states to test, if I recall correctly you do not set the bcg down on a table to see if it holds, but rather just turn the bcg facing down to see if the bolt slides out by the weight of the bolt itself. I have it saved somewhere on this laptop, I'll try to find it.

[PeteDavis]

Thank you to all.

Pete Davis

[FRB6.5]

Re; gas rings, buy good parts from a trusted vendor, not the cheapest ones you can find. Sadly is yet another item where there are lots of poor quality China made parts floating around.

[Klem]

Lastrites,

That is how we were taught as well. Hold the carrier vertical facing the ground and see if the bolt moves forward by its own weight.

[Old Bob]

That's not how the manual states to test, if I recall correctly you do not set the bcg down on a table to see if it holds, but rather just turn the bcg facing down to see if the bolt slides out by the weight of the bolt itself. I have it saved somewhere on this laptop, I'll try to find it.

I've been using the Marine Corp TM: TM 05538C-23&P/2 for assembly/disassembly, inspection criteria & torque specs. Under PM Checks & Services it says pretty much the same thing as the Army/AF/CG manual in regards to worn bolt rings but the wording is a slightly different. This manual never leaves my work bench & I refer to it often.

[biodsl]

Thanks, guys. Everything I learn about AR15's I learned from the Internet so it must be true. :o Gas rings on all of my bolts resist their own weight but not the weight of the carrier. Good to go it would appear.