AR15 Help

[bellarum]

Maybe try plugging the chamber end of the barrel and blow compressed air down the barrel from the muzzle and see if you feel the air coming from the gas tube? Not sure if that will work but might be worth a try. Maybe loosen the gas block enough to move it and move it slightly back and forth to see if there is a sweet spot where more air comes through while blowing through it and try to lock it in there? Good luck man!

 

[Archer762]

I had this problem and thought it was my upper, but it ended up being the buffer tube slightly misaligned. Since you say you replaced yours, it's possible you put it back on slightly off, causing the bolt to rub inside the tube and bind a little

 

[NWShooter44]

I hade the same thought. I took it apart and re assembled it. Need to go out and test again

 

[Velzey]

I had this problem before, it was rather odd. I never ever thought it could happen.

I had shot some reloads thru it and popped a few primers on some well used brass. Guess where the primer went to after it came out? Yep I spent hours and hours trying to figure out why the damn thing would not cycle, then I looked inside the gas key, the primer was sealing it up perfectly!

 

[NWShooter44]

Is there a specific way to tighten down the gas key to the carrier or do you just torque it down tight?

 

[speeddemon94]

Torque down to spec and then it should be staked in place.

 

[NWShooter44]

What spec and how do you stake it

 

[speeddemon94]

56 inch pounds and there is a tool to stake it if you really want to do it right. I'm in class so I can't post a picture.

 

[osprey]

55 inch pounds should put you where you need to be and you can stake with a center punch in two or three spots at the edge of the fastener heads. Search utube for a demo. Make sure you use soft jaws in the vise if you use a punch otherwise buy the stake tool.

 

[NavyBob]

Everything has already been brought up. The only other item would be ammunition. What are you using to test. Maybe your setup is sensitive to underpowered rounds. If you are using Tula lacquer coated russian ammo, it could be held up. Try a hotter premium Hornady.

One of my AR's simply will not eat anything Russian, but I throw a hot Zombie in the chamber and it works perfectly.

 

[mjbskwim]

They also put a new gas block on and new gas rings

Sounds like you took it to a car dealer's shop............just throw parts at it,that'll fix it!

Remember the movie Forrest Gump? Well these rifles were in fact,made so kids like him could take care of them.
Like my Ironhead,don't overlook the real simple sh!t,cause it's simple

 

[sauerwilly]

First thing I did was to add all the usual magpul furniture.

Do you have a BAD lever installed? They can cause similar issues on some rifles. Even if you don't, check your bolt catch to make sure its not the issue.

 

[NWShooter44]

Yes I do have a bad lever on it

 

[sauerwilly]

Unless I misread, you said the bolt would lock back randomly? If none of the other suggested fixes work, remove the bad lever see how it does. Are you using a CAR buffer or H?

 

[bellarum]

+1

Do you have a BAD lever installed? They can cause similar issues on some rifles. Even if you don't, check your bolt catch to make sure its not the issue.

 

[NWShooter44]

Update:

So I was tired of not having a functional gun so I took it up to Brian at Rapid Fire Arms in Sandy.

He found the gas block that curts installed was nowhere close to lining up with the gas port in the barrel. Installed a new Troy RGB and bingo, functions!
The bolt locking back problem he found was due to the spring and plunger being missing from the bolt catch, probably from when the BAD lever was installed. Replaced those and bingo! It now runs flawless, with multiple different loads!

I will NEVER support Curts again after this! They took only my upper, threw a bubblegum gas block on and never test fired, and returned it saying it was fixed. They would have never known about the BAD lever issue since they didnt take the lower receiver for work.

Also, I highly recommend working with Rapid Fire! They have always been good to me, and updated me on every step of the repair via phone call. Work was done quickly and properly and they are great people!




Cliffs:
gas block bad, replaced
missing spring and plunger for bolt catch; replaced
result: functional rifle

 

[.45's and .38's]

I'm in happy valley and am curious where rapid fire is.

 

[NWShooter44]

Rapid fire is in the middle of downtown Sandy right across from leathers gas station

 

[cookie]

Silly question Is the rifle well oiled? Then try a different mag. Then do the posted list. This is a learning experience. Try ARFCOM and M4 carbine.net web sites. I went out to the range last Sunday and a guy was having trouble with a Rem semiauto rifle. I finally went over to see what the problem was . I gave him my oil and said get it wet . The rifle went from jamming, not cycling, to sticking rounds in the chamber to a rock and roll machine. Rem 7400, I think was the rifle any way it was most impressive.

 

[.45's and .38's]

looks like he solved the problem

gas block bad, replaced
missing spring and plunger for bolt catch; replaced
result: functional rifle