I figured I'd start a new thread. My SW mp15 will not cycle. It's a single shot. It all works fine manually, feeds, fires, ejects by hand but the bolt is not cycling when shooting. I would presume something blocking the gas system. I had some long ar gas tube pipe type cleaners and ran it thru with no obstructions. I'm not sure if it got thru the hole in the gas block though. The key mates up to the tube ok.Any ideas? Thanks.
1st ar problems
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Yes I tried different ammo. The first shot works fine. Then you have to eject the round with the charging handle. It's acting more like a bolt action rifle.
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Try different mags, perhaps? Tapco makes okay mags for AK's and SKS's, but for AR's ... ehhhhhh, I dunno...
Easier/cheaper to try the simple stuff first before going at the internal bits. Remember, magazines are the #1 cause of problems with almost all semi-autos.
Easier/cheaper to try the simple stuff first before going at the internal bits. Remember, magazines are the #1 cause of problems with almost all semi-autos.
I think I found the problem. The gas tube retention pin was missing and the tube was not all the way in the gas block. I was trying to tap the pin out and all I was hitting was the end of the tube. In videos the pin tapped out rather easy. So I thought maybe it was not lined up proper so I pulled on the tube and it slid out. I could see the tip of the tube where I was tapping. It was forward of the hole. I definitely did not lose the pin. In the pic you can see where I was tapping just above the hole.
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Also I can see the burnt carbon just front of the gas tube hole. Sorry to say I think this was a factory problem. Nothing looks like it has been tampered with. I did not remove the a2 sight. Just took the hand guards off. No hammer, punch marks anywhere. Everything by the sight looks pristine. Hey, could this have been a Kalifornia compliant rifle? A single shot variation. LOL. By the way anyone know what size pin?
Thank you for that info.
The guy that sold it to me must have known. He said he put 5 or so rounds thru it. That should have been a red flag. Why would you shoot so few? Well gotta get back to the range to verify that it's fixed. All in all not a big deal if it's fixed. The rifle is in like new condition and for the price can't complain.
I just got back from the indoor range near where I work. Everything is hitting on all cylinders now. That's the good news. Bad news is the adj stock collapse when shooting at times. Not the worst thing I can always get a new one but is there any fix/adjustment for that before I spend any dough? LOL.
Yes. Everything works as it should. Press release. Slide into notch. Release lever. Seems secure when I bump the back of the stock but under shooting conditions it jumps out of it's notch at times.
How far into the hole does the lock pin go? It should go in about 3/8". If you lift up on the locking lever, you should be able to slide the stock off the back and look at the holes in the buffer tube as well as the locking pin. I'm guessing that there's a burr somewhere that prevents the pin from going far enough into the hole in the buffer tube.
You aren't shooting off a rest that is accidentally pressing the lever while shooting are you?
You aren't shooting off a rest that is accidentally pressing the lever while shooting are you?
No burrs. No rest. I was free handing just to test the rifle out. But what I did was punch the roll pin out that goes thru the screw/pin and turn it down a little so the pin sits further down in the hole. If that's not the problem then maybe the spring in the release is weak. We'll see. By the way your specs on the gas tube roll pin were spot on. Saved a little trial and error work. Thanks.
That should do it.
Normally the plunger should project far enough that you won't be able to slide the stock off the extension tube, no matter how far you squeeze the release mechanism. If you could squeeze it and slide the stock right off, the plunger wasn't adjusted for enough projection...which would also let it slip, like you were seeing.
Before I worked on it I tried squeezing the release and trying to pull the stock off but it stayed in place. I didn't try to Schwarzenegger it but I tugged on it. Probably just on the end of it's tolerance and stout recoil pushed it over.
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