Help with AR10 weird cycling issue

[Bevo]

Gun is as follows:

• Mega receiver set
• Seekins .308 16" barrel
• SLR AGB
• JP HP bolt in a Ballistic Advantage carrier
• Slash Heavy Buffer w/ recommended spring for A5 buffer tube
• Geissele SSA-E
• Suppressed

I have shot it in this configuration numerous times, including many hunts, with no problem. However, it was not behaving last time out.

The gun would cycle, pick up the next round, and appear to close the bolt all the way, but then click - no bang. It would allow me to fire the next round if I pulled the charging handle enough to pass the bolt back over the trigger and reset it, then let it fly back into chamber. Sometimes next round was fine, sometimes I'd get 3 in a row where I'd just get a click when pulling the trigger. It also didn't fire when dropping the bolt on a new mag a couple times.

Gun is relatively clean, not gunked up or anything. Happened with two different factory loads and my hand loads. What say you Hide?

 

[Edsel]

Is this a possibility?

 

[Makinchips208]

Sure its all the way in battery?

Does the click when it doesnt fire seem different than the good click when it would fire?

Couple weeks ago a friends ar would randomly click, leave a tiny mark on the primer, but not fire. Swapped several things around, then found the hammer was falling to almost like a half cocked. It was a drop in trigger that was faulty.
I dont know if the SSA-E would do that or not.

 

[Ernest 5.56]

Inspect the bolt face and firing pin

What do your primers look like?

 

[PhrogDriver]

Could it be bolt bounce? Maybe check the gas rings. The bolt might be going into battery then bouncing rearward, coming slightly out of battery, so the firing pin wasn't consistently striking the primer. Happened to me, and my gas rings weren't holding the bolt. A few dollars worth of new gas rings did the trick.

 

[Ernest 5.56]

People have had trouble with the single piece gas rings

 

[BenE]

Factory or handloads?

 

[Bevo]

View attachment 8673561

Is this a possibility?

No, but I’m going to pull the trigger and inspect everything.

 

[Bevo]

Inspect the bolt face and firing pin

What do your primers look like?

This was my first guess. Bolt face looked fine but I’m going to pull it, clean it, and take a closer look. Primers look normal.

 

[Edsel]

If it’s that dirty, maybe it’s just accumulated brass fragments in the firing pin channel, or something like that.

 

[stanley_white]

I gotta ask, does your rifle have a forward assist?

-Stan

 

[Bevo]

I gotta ask, does your rifle have a forward assist?

-Stan

Nope.

 

[bfoosh006]

Check to make sure you don't have a primer "disc" in the firing pin channel , from a pierced primer.

 

[nagantguy]

My first guesses folks above have already guessed but to reinforce- shit, brass piece of old primer in the FP channel and the JP one piece gas rings are great I hear except when they don’t work .

 

[mudholestomper]

If it’s that dirty, maybe it’s just accumulated brass fragments in the firing pin channel, or something like that.

That’s my guess. I haven’t had it happen on any of my 556 guns, but there’s violence going on inside the upper of my 308 gas gun, and I’ve had a brass shaving limit my firing pin motion.

I’ve had nothing but great experience with the JP one piece gas rings. I love the way they smooth out the cycling. I’ve got a JP bolt in my AR10 and one of my AR15s. No issues whatsoever.

 

[Bevo]

I pulled it apart and don't see any issues.

Based on info here and some back and forth with Chat-GPT, my guess is gas rings. Will replace and see if it fixes anything.