LMT AR-15 shoots only one at a time...

[ArcadiaGP]

Is this one of those special AR's only made for California residents?

 

[SmileDocHill]

I've been fortunate enough not to have had any real AR problems but I learn more about the details of how they function by reading these type threads than about anything else!

Great thread.

 

[phylodog]

Rvb is offering sound advice. The first thing I do in these situations is to load one round in the mag, shoot it and see if it locks back on the empty mag. If not the gas carrier key is the first thing I look at and is usually the culprit.

 

[peloe16]

had a situation like this. I had the wrong size buffer spring in the stock. replaced it and it worked like a charm. may have nothing to do with your problem, but same symptoms occurred.

 

[GlockRiver]

Have you messed with the trigger lately? Could be a disconnector or spring issue.

 

[10mmfan]

I had a problem like this with my first AR. I had a Bushmaster I bought back in 2001 that behaved like yours. Bushmaster's advice at first was to try different ammo with heavier bullets or some 5.56 instead of .223 I was using. This was of no help. Eventually, it was determined to be a problem with the gas key. It was somehow not applying all the gas needed to properly cycle the carrier all the way back. They had good service then and sent me a whole complete BCG within about a week.

 

[atalon]

Not trying to get on your case but one thing I have noticed is your not saying what type of powder you are using. 1 type will be high pressure at 23 grains and another type will be underpowered at the same grains of powder.

Please verify what powder you are using in your hand loads. I realize this would not affect the factory ammo you are using, but the reloads could be a dirty powder that clogging the gas tube.

 

[kedie]

LMTs are junk. Send it to me and I'll dispose of it properly.

 

[Squirt239]

Might sound stupid, but you might try giving the mag catch another turn clockwise. Just an idea. Had an AR problem and fixed it by doing such.

 

[bosaw]

PROBLEM SOLVED!

I tore down my LMT and started with checking the gas system. I used CVA Barrel Blaster and used the little red tube to get it into the gas tube. It took some time, but it loosened up somethings and was able to use my air compressor to clear the tube. It had some carbon and flakes of stuff, but I didn't stop there.

Next, I went after the gas key. I hit it with the Barrel Blaster and it promptly returned the cleaner to my face. Suspecting an obstruction, I grabbed my air hose and held it up to the gas key. I turn the key away from me thinking I wasn't going to get it in the face again. That didn't work out to well. The exit ports out of the bolt carrier got me this time... And my mouth was open! Almost got me in the eye too.

The obstruction in the gas key and bolt carrier was thoroughly cleaned and it wasn't until yesterday before I could test it out. It worked flawlessly. I'm glad it wasn't a California model.

After this experience, I would highly recommend using compressed air in addition to regular cleaning methods, but I will also recommend safety glasses and keeping your lips sealed while blasting.

Thanks for all the suggestions, I wish I was able to test it out sooner and get back on here sooner to give the results. Thanks again INGO people.

 

[Hookeye]

So what ammo gunked it up?
Saw a Colt SP1 gum up after 400 or so Wolf rounds.

 

[Mgderf]

Glad to see you got it figured out.

That damned flaky stuff can really do you in. I've seen similar problems with older cars. Gas would turn to lacquer on the inside of the tank. A flake would work loose and find the intake screen in the tank. Presto, you're out of gas. Wait a while and let the flake float away from the intake screen and now she'll start and run just fine, until it floats over to the intake screen again...

I've seen rust flakes inside automobile brake lines cause a lack of break pressure.

I've seen rust flakes build up in home plumbing pipes to the point that it stopped the flow of water to a faucet or shower.

When you start talking hundredths of an inch clearance, it doesn't take much of a flake of whatever to cause problems.

 

[bosaw]

So what ammo gunked it up?

I cannot say for sure. I bought the gun used and the seller specifically stated in his ad that he only used quality brass cased ammo. I'm guessing that's like someone who starts off saying, "Well, to be honest with you,..."

I did test steel Wolf .223 rounds, brass PMC 5.56 rounds, and some brass Prvi 5.56 rounds but it had the same problem. Once it was gone through and cleaned, it shoots anything like a champ.