AR-10 w/ noveske 18" barrel not cycling

[freestylmx]

I bought a custom made Armalite 308 with an 18" noveske barrel. It will not cycle anything. Pulling the bolt back by hand showed it was stopping too soon, it wont lock back. I took out the buffer and saw the screw in the back of the prs stock sticks out and hits the buffer. I removed it and cut it in half, put it back together and the buffer goes all the way back and locks. I thought problem solved, but it still wont cycle or lock back during firing.
Does anyone know what the gas port diameter should be on an 18" Noveske?
I cant figure anything else out. The buffer is the standard rifle buffer that weighs just over 5oz.
Anyone have any clues?
Also for some reason at first it would not cycle factory ammo but would cycle my reloads, so I thought weak ammo..but now it doesnt cycle anything at all, not even max pressure loads (book max that is)
Its still new with maybe 80 rounds through it (most all single fed) and bolt is used sloppy wet

 

[EricCartmann]

Re: AR-10 w/ noveske 18" barrel not cycling

This is a custom gun you fired for the first time right?

It appears you have the AR15 PRS and not the AR10 PRS. AR10 carriers are longer than AR15 carriers so you will need the longer AR10 PRS or longer AR10 buffer tube in order for the carrier to go all the way back.

However, you say the bolt goes all the way back now, are you sure about this? Does the bolt hold open work when there is an empty mag in place? Or bolt could be getting hung up somewhere and not properly going back in the tube during a live fire?

If bolt carrier does truly lock back when manually cycling and not getting hung up, it appears you have a gas leak somewhere or the gas port is blocked.

Also, did you check to see if the gas tube aligns with the bolt carrier key when the carrier is in the rifle? If it is not, then the gas will not properly kick the bolt back.

I know Noveske Barrels come with the gas block already installed, so I am pretty sure you have the correct gas port size in your barrel since Noveske is known for getting it right. However, you never know. I read awhile back that a lot of Eagle barrels had the wrong gas port size hole and these barrels were short stroking like your gun is now. They had to open up (drill) the hole to make it work right.

 

[BCP]

Re: AR-10 w/ noveske 18" barrel not cycling

assuming it chambers and ejects okay

1) wrong buffer/buffer tube/buffer spring
2) gas leak (misaligned gas block, bad gas tube, loose gas key on bolt)
3) gas port size

without being able to see it for yourself it's a bitch though. where do you live? maybe someone local can help you

 

[freestylmx]

Re: AR-10 w/ noveske 18" barrel not cycling

The buffer tube is the right size and the buffer/bolt move freely and bolt locks back manually now that I fixed the screw problem.
The gas key is on tight and staked and is aligned to the tube properly.
The buffer and spring are the correct ones. Its an AR-10 rifle buffer with an Armalite AR-10 spring. The buffer has all steel weights and weighs just over 5 oz. I was thinking of removing some weights but the buffer is already on the light side
It ejects the rounds but will not chamber any rounds. The bolt is not traveling back far enough to pick up a round or lock back after the mag is empty, but will go back far enough by hand.
Also, on a side note, I wanted to find out the twist rate of the barrel and I thought noveske printed it on the barrel but all mine has is the noveske logo then a 6 digit serial number..must be an older model? hard to tell exactly by using the cleaning rod method

 

[EricCartmann]

Re: AR-10 w/ noveske 18" barrel not cycling

You can see if the gas port in the barrel is lined up with the hole in the gas block. Sometimes you have to rotate or even push the gas block a little forward or backwards about the thickness of a dime to get it to line up.

 

[Jmilera]

Re: AR-10 w/ noveske 18" barrel not cycling

Take it apart and give it a good cleaning , check for gas leaking at the block, ( does it have a noveski switch block and if it does is it in the on or unsuppressed position) and if it's not a noveski switch block maybe it just needs to be tuned. Pictures of the gas block would help.

 

[DavidAR10]

Re: AR-10 w/ noveske 18" barrel not cycling

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: EricCartmann</div><div class="ubbcode-body">You can see if the gas port in the barrel is lined up with the hole in the gas block. Sometimes you have to rotate or even push the gas block a little forward or backwards about the thickness of a dime to get it to line up. </div></div>

Big Roger That.

http://www.armalite.com/ItemForm.aspx?item=EU0335

 

[2ndamendfan]

Re: AR-10 w/ noveske 18" barrel not cycling

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: EricCartmann</div><div class="ubbcode-body">This is a custom gun you fired for the first time right?

It appears you have the AR15 PRS and not the AR10 PRS. AR10 carriers are longer than AR15 carriers so you will need the longer AR10 PRS or longer AR10 buffer tube in order for the carrier to go all the way back.

However, you say the bolt goes all the way back now, are you sure about this? Does the bolt hold open work when there is an empty mag in place? Or bolt could be getting hung up somewhere and not properly going back in the tube during a live fire?

If bolt carrier does truly lock back when manually cycling and not getting hung up, it appears you have a gas leak somewhere or the gas port is blocked.

Also, did you check to see if the gas tube aligns with the bolt carrier key when the carrier is in the rifle? If it is not, then the gas will not properly kick the bolt back.

I know Noveske Barrels come with the gas block already installed, so I am pretty sure you have the correct gas port size in your barrel since Noveske is known for getting it right. However, you never know. I read awhile back that a lot of Eagle barrels had the wrong gas port size hole and these barrels were short stroking like your gun is now. They had to open up (drill) the hole to make it work right. </div></div>

The AR-10 and AR-15 use the same buffer tube. The only difference in the PRS stocks is the cheek piece. The AR-10 PRS cheek piece is about 3/8" shorter to allow for the longer bolt/charging handle pull. Many people have put a AR-15 PRS on their AR-10 and cut the cheek piece down. Since the buffer tube is the same length the AR-10 buffer is shorter. Basically a AR-15 carbine buffer.

Does it eject? Or get jammed up trying to?

 

[EricCartmann]

Re: AR-10 w/ noveske 18" barrel not cycling

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DavidAR10</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: EricCartmann</div><div class="ubbcode-body">You can see if the gas port in the barrel is lined up with the hole in the gas block. Sometimes you have to rotate or even push the gas block a little forward or backwards about the thickness of a dime to get it to line up. </div></div>

Big Roger That.

http://www.armalite.com/ItemForm.aspx?item=EU0335
</div></div>

Just thought about this.. he does not have an Armalite gas block so I don't think that spacer is needed. His gas block was installed by a Smith.. Smiths are not always precise with their work, so always good to double check.

 

[mtrmn]

Re: AR-10 w/ noveske 18" barrel not cycling

This a NEW CUSTOM gun? You need to get with whoever built it before you go tearing it apart and tinkering--In my humble opinion. They should be responsible for making it work. Just sayin'

 

[freestylmx]

Re: AR-10 w/ noveske 18" barrel not cycling

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mtrmn</div><div class="ubbcode-body">This a NEW CUSTOM gun? You need to get with whoever built it before you go tearing it apart and tinkering--In my humble opinion. They should be responsible for making it work. Just sayin' </div></div>
It was bought 3 years ago and put in the safe and never fired untill recently, think its a little too late for that even though you are right..when you buy a $2500 rifle you expect it to work

 

[SONIC SAAMI]

Re: AR-10 w/ noveske 18" barrel not cycling

First off the AR-10/AR-15/M-15 Rifle Receiver Extension are all the same size.
http://www.762sass.com/product.php?p=46&cid=7&session=7f0fda6a8e0ac827fa5e2e1c0e683e55

A AR-15 PRS will work on a AR-10 if you trim the cheek riser so the C/H will go back all the way.
A AR-10 PRS will work on a AR-15 with no mods.

It sounds to me like the gas block is not alined with the gas port or you have a gas leak on the rifle.

What do the gas rings on the bolt look like?
Is the gas tube roll pin installed in the gas block?
Can you see any gas leakage?