Bolt Failure today..

**markm** · 05-17-14, 17:39

Had my suppressed 11.5 lock up today. Thought it was a blow primer, but it was a bolt lug failure. The busted piece was behind the cam pin in the BCG.

After this... I put the bolt back in and continued the shoot. Maybe 40 more rounds in this gun. when I got home, the next lug (above) was busted off and sitting in the Barrel Extension.

**Dead Man** · 05-17-14, 17:44

How many miles on the bolt?

**markm** · 05-17-14, 17:48

Not EXACTLY sure. I'd estimate 2000-4000 rounds. This bolt is NP3'd and bought that way, but hasn't appeared so since about 100 rounds or so. I'm not sure I want to say what bolt it is yet. This is my first busted bolt, and I don't think it's anything other than SHIT HAPPENS. This is NOT A BCM or COLT item.

**WS6** · 05-17-14, 17:57

Robert Silvers refused to have any coatings/treatments done to this AAC BCG bolts due to hydrogen embrittlement potential. I wonder if NP3 can result in such? I am not up and up on it, so I don't know.

**markm** · 05-17-14, 17:58

Originally Posted by WS6

Robert Silvers refused to have any coatings/treatments done to this AAC BCG bolts due to hydrogen embrittlement potential. I wonder if NP3 can result in such? I am not up and up on it, so I don't know.

Yeah. I'm not sure if that's an NP3 issue or not.

**WS6** · 05-17-14, 18:05

Originally Posted by markm

Yeah. I'm not sure if that's an NP3 issue or not.

Do you know if this is a C158 or 9310 bolt?

**markm** · 05-17-14, 18:07

I don't. I'm not sure if I'll send it in. I'm certainly not blaming anything on any manufacturer yet. The bolt is marked MPI. I can't remember if it was described as C158 or not though.

**WS6** · 05-17-14, 18:15

Originally Posted by markm

I don't. I'm not sure if I'll send it in. I'm certainly not blaming anything on any manufacturer yet. The bolt is marked MPI. I can't remember if it was described as C158 or not though.

It lasted several thousand rounds. I'm not sure that anyone "is to blame", regardless. Still, I personally would never buy another one like it simply because it did fail prematurely and I've left my NP3/QPQ/Unicorn Blood bolt phase and gone with Mil-Spec and not had any issues.

My former roommate and I worked over my Surefire suppressors last week and he has a RCA BCG, and I have a Mil-Spec BCG. Both our weapons ran fine, both cycled by hand afterward with about the same "feel" to them all caked in carbon, and both of them cleaned up the same way, except mine had a tiny bit of carbon on the tail of the bolt after wiping with a paper-towel and his RCA BCG did not. Also of note, his cam-pin and bolt lugs showed 0 wear while mine showed some.

Still, I have had a RCA bolt peen and deform lugs on me before. Never a good Mil-Spec one.

Anyway, just my ramblings. I'm surprised a man of your 17-7 Mil-Spec buffer spring using, CS spring hating ideation would ever run something covered in NP3 :P