My SINGLE SHOT AR- Not any more!

[prproulx]

I bought this almost new on the board. It is an Armalite 11.5". It looked unfired when I got it so I have no reason to think the previous owner abused it.
I finally got it out to the range and from the onset, it refused to lock open on the last shot.
It frequently would not strip a round, and twice a round got hung up on the feedramps.
I used three different mags, the Armalite ones, some Brownells and a Bushmaster.
All were equally unreliable.
I stripped it when I got home and looked at the buffer.

Then the rear of the carrier

The feed ramps

And the spring outside the stock

It seems like the buffer isn't going all the way back and that's weird marks that I've never seen before.
Any ideas?

 

[HeadDamage]

That spring looks like it might be the regular lenght unit not the carbine one.

 

[dangertree]

Measure your action spring. I'll post the A2 and Carbine lengths in a couple of hours unless someone beats me to it.

 

[hoddie]

Clip about 3-4 coils off the spring. That should help you out.
YMMV,
Hoddie.

 

[prproulx]

Spring is exactly 11"

 

[angryeyebrows]

I just pulled the spring from my carbine and it's 10.5". +1 for Hoddies Idea.

 

[Jamie]

looks like a rifle length buffer too that would cause you some grief


Jamie

 

[Urban_Ops]

have you checked the gas ring alignment ?

 

[prproulx]

have you checked the gas ring alignment ?[/QUOTE

I'm mechanically challenged. How would I go about checking these gas rings?

 

[HeadDamage]

The buffer is correct.... gas rings would be good to check. I once helped a CGN member with an upper he got on here. It wouldn't cycle, it turned out not to have a gas tube.

 

[PaveHammer]

What ammunition was used?

If you're using particularly anaemic ammunition, you will definately see signs of short stroking.

 

[prproulx]

Get a load of this! I went to check the gas tube and noticed it was a bit twisted.
I started to remove the roll pin, and found out there was no roll pin!

Honestly I don't think this thing was messed with.

 

[HeadDamage]

That will not let enough gas pass to work the action if that is the way it lines up when in use.

 

[smgcon]

Head Damage is right!

The twisted gas tube is shutting off some of the gas. Straighten it out and add a roll pin, and it should be back to normal.

I have some carbine length springs that are slightly longer than others, and all buffers get worn anodizing from the rear of the carrier. Good eyes Pat for seeing the missing gas tube retaining pin!

 

[prproulx]

A factory rifle without gas tube roll pin????

Someone at Armalite need to be spanked and stomped!

I don't think it fell out by itself based on my experience with these things.

I'm just glad it was a simple fix. I will post an update when I get a roll pin that is on it's way thanks to BBB.

 

[Hungry]

badboybeason is a great source for AR parts. He is always coming to rescue (yours truly also) of many CGNutters.

3 cheers !!

 

[highspeedlowdrag]

Regarding the marks on your buffer face: It's normal to have some wear on the face over time. If you're concerned that it's wearing more or more quickly than normal, check the rear face of the carrier (the side that contacts with the buffer). Usually the culprit is the small "cut out" at the base (that allows the carrier to ride over top of the buffer detent). Sometimes this area can have some slight/rough imperfections that will cut into the softer aluminum face of the buffer. All you need to do is use a small needle file to touch up this area (very lightly - it doesn't take much) to get rid of any high/rough spots in this area. This should reduce the amount of premature wear that is showing up on your buffer...

hsld.

 

[NavyShooter]

Don't order one gas tube pin, order 2-3. That way when you (someday) feel the need to take your gas tube off and replace it, you have a spare onhand to break (drop into the carpet and lose).

NS

(Voice of experience....vacuuming in the gun room is amusing over here.)

 

[cybershooters]

Whenever I hear this story, 99.9% of the time it's a problem with the gas tube or the gas key, getting carbon blocking the gas key is quite common.

 

[prproulx]

I got the roll pin and some Winchester 62 grain ammo and went out to shoot.
No failures of any kind. Here is my best group at 50 yards with iron sights.

Not bad for a poodle-gun!