Chipping AR15 Bolt Face

[meh249]

I have two PSA AR15s. Both of the bolt faces started to chip immediately with shooting. One is a 14.7 to 16” pin and weld and the other is their 20” A2. I rebarreled the 16” and changed the upper assembly on the A2. Would that somehow cause my bolt faces to chip so badly? The two PSA bolts are marked as MPI. The one that isn’t chipped as bad was mostly PMC Bronze .223 and the other started off with XTac M193. I’ve probably shot around 150 rounds and 400 rounds respectively. It’s been about a month since I’ve emailed PSA’s warranty for the 16” and I have yet to contact them about the 20”. Any ideas or maybe advice? Thank you guys so much!

 

[ikeo1]

I’ve never seen that before. Considering your using factory def doesn’t seem normal. Have you seen this problem on other bolts?

Following.

 

[heynice]

Never seen that before either. The rings look the same size as the primer pocket on the cartridge, is there any chance something is off with the ammo?

 

[meh249]

So looking at my brass, it seems like there’s gas leaking from the primers. Leaking primers is probably the primary cause. I’m throwing out a lot of my brass. The confusing thing is when I shot the PMC Bronze, I thought it was still chipping my bolt face so I decided to shoot my reloads. The PMC Bronze didn’t have leaky primers, but it again it seemed like it was chipping still…

 

[ikeo1]

So looking at my brass, it seems like there’s gas leaking from the primers. Leaking primers is probably the primary cause. I’m throwing out a lot of my brass. The confusing thing is when I shot the PMC Bronze, I thought it was still chipping my bolt face so I decided to shoot my reloads. The PMC Bronze didn’t have leaky primers, but it again it seemed like it was chipping still…

So you reload, do you swage your primer pockets? Even if there was leakage that wouldn't cause chipping. There has to be a gap where the bolt face isn't sitting flush is my assumption.

For your reloads, you can probably test this if you have a chrono and do a side by side with factory and your own reloads. Or even just running through your reloads to see if you have consistent FPS. You could also get more consistent by using the same head stamps.

 

[meh249]

Yeah I mix my casings. I know I shouldn’t but I’m not going for precision. I swaged my primer pockets, but I might reamed too much material on some casings. The casings that leaked gas were kind of random. They both were various manufactured of .223 and 5.56. I use the chamfer tool to ream out the crimp and leave a swage. Sorry if that’s confusing I don’t know how to describe it hahaha. It’s also likely that I did it unevenly since I do it all by hand.

 

[Warpspeed]

That seems excessive - are you having any primers fall out after firing ?

 

[meh249]

I’ve actually never had a primer fall out. I just cut out too much brass.

 

[CamAW]

Are you shooting reloads with Winchester #41 primers? There's been reports of defective batches of primers.

Here's a thread with pictures on AR-15 .com

WARNING! Defective Winchester #41 primers on the shelves. - AR15.COM

Firearm Discussion and Resources from AR-15, AK-47, Handguns and more! Buy, Sell, and Trade your Firearms and Gear.

www.ar15.com

 

[meh249]

No I don’t use military primers. I use CCI 400 SRP. I think some of the primer pockets may have been swaged too much or became too loose on the primer because some of the spent casings have small pinholes at the edges which mean leaking gas. I’ve since began to throw out these spent casings and swaged the pockets less.