Burrs on rear edges of bolt locking lugs on AR-10: dangerous or poor quality?

Hellgate

Hellgate

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PSA 6.5 CM with adjustable gas block. This gun has never fired a factory round. I am anal about brass prep and not overloading. It has had a couple hundred rounds through it in the process of working up deer loads with 129gr, 140-143gr bullets. I have been using W760, H4350, and R-26. I might find early case stretching after 4-6 firings on the brass whereupon they are tossed. When cleaning the rifle and BCG I found burrs on the rear edges of several bolt lugs. The gun fires and ejects brass at 1-2 o'clock. When brand new we set the gas port to function with the lowest powder charge we might use for a coyote load with the 95gr V-Max bullet.
Are these burrs just normal wear & tear or a sign of a major problem? They are about .02" deep and .04" tall on the rear corner of 3 or 4 lugs. I've never seen anything similar on an AR-15.
OK to file the sharp edges of where the lugs are gouged?
 
Is this a Gen 3 PA-65?

Probably not poor quality, but most likely suffers poor quality control.

The integrity/strength of the BCG is probably acceptable, it's the hand finishing that is lacking. They have to cut corners somewhere, so the hand finishing was probably minimal at best.

My 3 PSA PA-10/65 1st/2nd Gen rifles all had cycling issues, bad extractors, ejectors and low weight buffer issues. I replaced the BCGs and added H3 buffers to all 3 and fixed every issue. I purchased them 2nd hand but NIB/LNIB, I think $400 - $450 each, so I wasn't too upset. One of the 16" 308 rifles is one of the most accurate I own and wears thermal all the time, it's also one of the lightest large frame ARs I own. Overall, the metal finish is subpar on all 3 compared to the DTech, AR15 Performance, Tromix, Wilson and Aero rifles I own.

I would buy a medium grit and fine grit stone and de-burr the lugs. I have a couple of extras, if you want to drop me a PM, I can send you a couple via mail, just pass along the courtesy to a fellow gun owner if given the opportunity. I wouldn't use a file and I sure wouldn't touch the "face" of the lugs, just the edges.


I have had less than 3 hrs sleep in over 24hrs, excuse me if I sound disoriented. Work has been insane.
 
I do not have a photo storage site and this site won't let me upload from my computer so I don't have pics. I do not know exactly which model it is. It is my brother's rifle that he got last year. He does not reload. I have been reloading for family and friends since 1965. I will take a fine stone to the lips of the burrs but leave the original surfaces alone. I appreciate the suggestion and offer, Darryle.
 
Originally Posted By: HellgateI do not have a photo storage site and this site won't let me upload from my computer so I don't have pics. I do not know exactly which model it is. It is my brother's rifle that he got last year. He does not reload. I have been reloading for family and friends since 1965. I will take a fine stone to the lips of the burrs but leave the original surfaces alone. I appreciate the suggestion and offer, Darryle.

I will PM you my email address and you can send pictures to me and I will post them up
 
It’s gonna have to wait a bit. The rifle is at my brother’s house in a safe and he’s out of town. I’ll email him to take some pictures that I will send. Thanks so much for your patience.
 
Looking at the pictures, I would have him contact PSA using the warranty contact.

If he doesn't want to wait, I would have a local smith look at the barrel extension lugs and buy a Toolcraft BCG once he repairs the BE lugs if needed.
 
Dang, never saw that one before. Definitely call PSA, it might be hard to get through right now. I'm thinking the cam pin slot isn't quite right, and it's not rotating the bolt enough when opening? Just a guess.

The bad thing is they'll probably replace the whole upper, but if the BE looks similar to the bolt it probably should be.
 
That bolt is not right, I wonder why the firing pin hole is so big and why it is showing signs of erosion.

What ammo is he running?
 
He is shooting:
143gr ELD-X 38.5gr H4350
140gr Accubond 37.5gr H4350
140gr Partition 37.5gr H4350
129gr Interbond 37gr H4350

I suspect these are not that close to max loads as they are only going about 2450-2470fps. They are in Starline brass.
I see where Johnny's Reloading Bench was shooting the 143 ELD-X with 43 gr H4350 @2750fps in a bolt gun. I followed published loading data. We tuned the adj gas block by dialing it to function on the lowest listed powder charge for a 95gr Vmax. Could the gun just be way over gassed? These "lesions" on the locking lugs were there from the get go when working up hunting loads starting at the mid range of powder charges and working up until I saw pressure signs on the case head or primer. No pierced primers so far.
 
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Originally Posted By: C.JayI am going to go out on a limb and say that bolt is not 158C

It definitely appears to be very soft.

I would order a Toolcraft single ejector BCG and send that one back to PSA and see what they say.
 


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