Colt commando upper starting to get froggy

[The Dumb Gun Collector]

I had two guns start to act weird yesterday!

My recently SBR'd AR with Colt Commando Upper had two odd malfunctions yesterday. First, I had a failure to ignite. I didn't notice if it was out of battery. I just kicked it out. It worked on the second shot. The second malfunction was an empty case stuck above the bolt, oddly, with an unfired cartridge in the chamber (the empty case was sticking out of the ejection port.

Background,

I have had this upper for a long time (about 7 years), I have shot if with thousands of round of steel, 22, brass, etc. It has gone through many phases...

https://www.m4carbine.net/showthread...ars&highlight=


I don't clean it religiously, but I do clean it every few outings. It isn't disgusting right now.



I was running it with 55 grain Hornaday Frontier. That ammo has run perfectly in every gun. I was shooting it with my Surefire Socom as usual. I will say recently I have been shooting it with Tula steel without the suppressor and it was running fine. I wonder if it is finally over gassed?

So, AR masters....What say you? Give me your best diagnostic tips and I will do what I need to do. If I have to replace the barrel and gas system I will probably just buy a whole new assembly. I really dig the way I have it setup these days..


IMG_2910 by stoiclawyer, on Flickr

[Sam]

Check your extractor, replace the extractor spring and maybe install the little rubber gasket thingy.

If all else fail, give it to me.

[georgeib]

Could also be the old shooting brass after shooting steel thing. Clean the chamber thoroughly, try again.

[sinister]

You probably need a new barrel.

[markm]

I was running it with 55 grain Hornaday Frontier.

That's what we (in the high speed tactical community) call a "CLUE)!!

[The Dumb Gun Collector]

Is that not good ammo in your experience?

[markm]

Is that not good ammo in your experience?

There was quite a bit of chatter in another thread about it being poor quality. The accuracy is awful, but the stuff we have shot did run ok. The bottom line is the ammo would be my first guess.

[Clint]

Yes, give the extractor a good cleanjng and inspection.

If the extractor spring has over 6,000 rounds on it, replacing it with a new Gold spring would be a good idea.

Check your extractor, replace the extractor spring and maybe install the little rubber gasket thingy.

[bamashooter]

Clean, lube, another known decent brass ammo. If a no go, I'd go with a quality extractor assembly replacement.

[The Dumb Gun Collector]

I cleaned it up paying particular attention to the extractor and chamber.. Replaced the buffer spring (which was visibly shorter) and fired 100 rounds of federal 55. Functioned fine but noticed it was ejecting around 1 o'clock. Might be time for a h3-4 buffer?