AR-10 Noveske N6 Jam

[Bystander]

I have put together an AR-10 Noveske N6 with 21" barrel and took it to the range to test fire the first time today. The AR-10 keep getting jam on every round, and I have to manually pull the charging handle to eject the shell on every shots. I noticed the bolt got push back each shot, but not far enough to eject the shell. I have no idea what's wrong and/or where to start to look for issue on the AR. Any advises on what to look for, and/or how to fix this issue is greatly appreciated. Below is the of the AR-10

Noveske complete upper with 21" barrell
I replaced the flash suppressor came with the upper with the JP tactical compensator
Noveske N6 lower
Geissele SSA trigger
Magpul PRS stock for AR-10

I was using American tactical 7.62 x 51 mm, 150 gr. rounds

Thank you

[xibunkrlilkidsx]

spring in the stock to strong? adjustment of gas flow?

did you assemble the lower? Disconnector spring?

[Tony.]

I would try different brands of ammo.

[joemama]

I have a n6 lower I built with an armalite 20" upper. It has the same problem yours does. I found it tends to only happen with crap ammo. It has run winchester and remington .308 just fine but the cheap stuff I find doesnt like to eject. Its so bad that it wont even reset the hammer. Try switching up the ammo with something thats better quality and see if that helps, and also lube it up a lot before shooting.

[Oregonish]

http://noveskerifleworks.com/cgi-bin/imcart/display.cgi?item_id=21-762&cat=98&page=1&search=&since=&status=

This rifle is designed and intended for use with high quality 7.62x51 NATO ammunition.
Some commercial .308 ammunition may not function through this rifle based on improper projectile design for a semi auto or the lack of a staked primer.


Facepalm.

[ar15barrels]

Check gas block alignment with the gas port.
Check that the proper buffer and spring are being used according to what type of buffer tube you are using.

[joemama]

http://noveskerifleworks.com/cgi-bin...since=&status=


This rifle is designed and intended for use with high quality 7.62x51 NATO ammunition.
Some commercial .308 ammunition may not function through this rifle based on improper projectile design for a semi auto or the lack of a staked primer.


Facepalm.

I believe that 7.62x51 has less pressure than .308, kinda the opposite of .556 ammo and .223. I'm using and armalite upper but it seems to be the exact same issue and it was fixed by switching ammo, I think the junk ammo may not have had enough of a charge to blow the bolt back far enough to eject, reset hammer, and grab another round and chamber it.

[ar15barrels]

308 ammo runs at higher pressure than 7.62x51.

[swerv512]

sounds exactly like what happened to a friend of mine- turned out to be gas block/port alignment issues....

[Bystander]

Thank you very much for everybody feedbacks. I will definitely look into it.

[Bystander]

spring in the stock to strong? adjustment of gas flow?

did you assemble the lower? Disconnector spring?

The buffer and spring bought new from Riffle Gear. I am not sure if the buffer spring is too strong, but there is no adjustment for the gas block.
yes I did assemble the lower.

Thank you

[Kiba]

Before tearing into the rifle try known good "control" ammo first. When I had problems with my AR-10 the first thing Armalite's tech support asked is if I had tried FGMM.

Check gas block alignment with the gas port.
Check that the proper buffer and spring are being used according to what type of buffer tube you are using.

Very good advice. While checking alignment of the gas port also make sure there are no obstructions (machining burr in the barrel, gas block, or tube.)

I'd also like to add:

Make sure your BCG is sufficiently lubed.
Check the gas rings on the bolt, see if anything is amiss.
Verify the carrier key is tight (it should be staked)

My AR-10 build that used an Armalite upper had similar issues to yours initially; it would usually eject just fine but nearly every time it would not feed the next round. Either the bolt would get hung up while stripping the next round or the bolt would short stroke and close without chambering a round at all. Also, the bolt would not lock back against the bolt stop if you only loaded up one round and fired which confirmed it was short-stroking. I checked all the usual suspects-- proper buffer & spring, gas block was aligned properly, the barrel port / gas block / gas tube were not obstructed in any way, the carrier key was tight & staked, the gas rings were good.

After some help from the calguns crew (Randall included) it seemed likely the gas port in the barrel was undersized. A call to Armalite tech support confirmed that the gas port on the barrel was under their minimum tolerance.

Armalite's tech support suggested everything that I had previously verified on my own and also asked if I had used known good "control" ammo like FGMM to confirm the malfunction. At that point they said to send it in but with a little persuasion they gave me the nominal diameter & tolerance for the gas port on my particular upper and I was able to fix it myself.

I'm not saying to go and drill out your gas port as the first step (that should be the last step-- and only if everything else checks out!) but check everything that has been mentioned. Any of them individually or a combination of them could be causing the malfunction.

[Bystander]

Thank you Kiba for the valuable information.

Before tearing into the rifle try known good "control" ammo first. When I had problems with my AR-10 the first thing Armalite's tech support asked is if I had tried FGMM.



Very good advice. While checking alignment of the gas port also make sure there are no obstructions (machining burr in the barrel, gas block, or tube.)

I'd also like to add:

Make sure your BCG is sufficiently lubed.
Check the gas rings on the bolt, see if anything is amiss.
Verify the carrier key is tight (it should be staked)

My AR-10 build that used an Armalite upper had similar issues to yours initially; it would usually eject just fine but nearly every time it would not feed the next round. Either the bolt would get hung up while stripping the next round or the bolt would short stroke and close without chambering a round at all. Also, the bolt would not lock back against the bolt stop if you only loaded up one round and fired which confirmed it was short-stroking. I checked all the usual suspects-- proper buffer & spring, gas block was aligned properly, the barrel port / gas block / gas tube were not obstructed in any way, the carrier key was tight & staked, the gas rings were good.

After some help from the calguns crew (Randall included) it seemed likely the gas port in the barrel was undersized. A call to Armalite tech support confirmed that the gas port on the barrel was under their minimum tolerance.

Armalite's tech support suggested everything that I had previously verified on my own and also asked if I had used known good "control" ammo like FGMM to confirm the malfunction. At that point they said to send it in but with a little persuasion they gave me the nominal diameter & tolerance for the gas port on my particular upper and I was able to fix it myself.

[Solidsnake87]

Like others have said, check the gas block alignment.

A likely problem is using an AR-15 buffer instead of a 308 buffer. Make sure you are using the correct buffer or your rifle will jam on EVERY shot. I've seen this problem in some fulton/dpms AR308s I put together.

[Dhena81]

Sell it to me. Or lube the BCG don't be stingy with it either.