Bolt Face Pitting

[AR-10 Shooter]

In addition to the erosion ring around the firing pin hole I've noticed pitting and/or gouges on the bolt face.

I built this rifle four years ago and am now getting around to working up some loads for it. The BCG is DPMS and I've fired less than 300 milsurp/reloads through it.

Is this normal? Should the bolt be monitored or replaced and if so which manufacturer?

Thanks in advance for the advice,
CT

 

[ORD]

Re: Bolt Face Pitting

First off...do you have any pics by chance (these kinds of questions are always easier to address when you can see the problem)?

Second, what kind of "surplus" ammo did you run through it? If it was corrosive (even mildly), that might explain the problem you are describing if the bolt (and the rest of the rifle) wasn't timely and appropriately cleaned after you shot it.

Aside from that, have you tried just cleaning the bolt thoroughly? I only ask because aside from some brass marks and the primer pocket ring, it is common for AR bolt faces to have some degree of crap build-up (it is a DI AR...they get crap caked damn near everywhere...although 300rds is pretty low)!

It may be possible that what you are seeing can be easily removed and returned to "normal" without having to replace the bolt.

If it is actually gouged or pitted (like from rust or other corrosion), then that is certainly NOT normal (especially considering how little the rifle has been shot) and depending on the extent of the damage, I'd look at getting a replacement after you have checked the rest of the rifle (barrel, gas system, and throughout) for any signs of corrosion (problem could be larger than just the bolt face).

 

[jpach]

Re: Bolt Face Pitting

Is this a .223/5.56?

 

[ORD]

Re: Bolt Face Pitting

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jpach</div><div class="ubbcode-body">Is this a .223/5.56? </div></div>

From his user name (AR-10 Shooter), I took it to be a 308, but that was an assumption on my part.

If in fact it is a 223/5.56...disregard what I said about corrosive ammo. I have never, in many thousands and thousands of rounds of well-wasted surplus ammo, seen any that was corrosive.

 

[colchester]

Re: Bolt Face Pitting

Could be caused by pierced or leaking primers. It only takes a couple bad ones to jack up the bolt face. As mentioned pics willl help

 

[AR-10 Shooter]

Re: Bolt Face Pitting

Sorry guys,

It's an AR-15. The ammo shot through it is late 70s PMC, M193, a handfull of Hornady and my reloads.

I'll see if I can get a pic uploaded which should be worth a thousand words.

Thanks,

CT

 

[81Z4ME]

Re: Bolt Face Pitting

My M1A has had pits in the bolt face for 15 or 20 years. Works and shoots just fine.

 

[jpach]

Re: Bolt Face Pitting

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ORD</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jpach</div><div class="ubbcode-body">Is this a .223/5.56? </div></div>

From his user name (AR-10 Shooter), I took it to be a 308, but that was an assumption on my part.

If in fact it is a 223/5.56...disregard what I said about corrosive ammo. I have never, in many thousands and thousands of rounds of well-wasted surplus ammo, seen any that was corrosive. </div></div>

Same here lol!

I just figured it was an AR-15 and asked if it was a 5.45x39 gun or something, although I was already pretty sure DPMS didnt make any 5.45 uppers or even bolts.

Ive never seen any corrosive 5.56 either.

 

[samnev]

Re: Bolt Face Pitting

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 73 fastback</div><div class="ubbcode-body">Could be caused by pierced or leaking primers. It only takes a couple bad ones to jack up the bolt face. As mentioned pics willl help </div></div>

Sounds like you had a primer or 2 leak and erode your bolt face. It doesn't take many if the leak is severe enough. I have had it happen to me 2X with federal primers and the first time it dug s hole in a new SR 556. However it's not a problem unless the firing pin hole gets eroded. Then replacement is required.