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View Full Version : New to ARs, jamming problem


dirkman55
04-27-2010, 4:47 PM
Just took my new AR (bought off a Calgunner) to the range for the first time and had some serious jamming issues. I think it might have been related to the mags I bought (10/30 PMAG) because it didn't seem to be an issue with the stock 10 rounder. Ultimately the spent casing was not clearing before the bolt came back and dozens empties got smooshed as it tried to close. Advice anyone? Thanks in advance. CMMG lower and upper if that helps.

ChrisO
04-27-2010, 4:49 PM
Did you lube it? Run it WET.

dirkman55
04-27-2010, 4:51 PM
It was pretty dry, lubed the crap out of it after the first couple, but the problem continued.

HK Dave
04-27-2010, 4:53 PM
According to what you said... it looks like it might be your pmag?

Try the stock 10 rounder and see if you have issues at all.

socalshooting
04-27-2010, 4:53 PM
When he says run it WET, he actually means thoroughly clean and lightly coat all moving metal contacting surfaces with CLP (or your lube of choice) and one or two drops into the gas ring holes visible from the ejection port. Don't just dump the whole bottle in there.

That aside, your problem sounds like an ejector issue.

Exposed
04-27-2010, 4:54 PM
could be short stroking. Usually has to do with a gas leak somewhere. Check gas tube, gas key, and gas block. Make sure all these are tight and not loose or have any play at all.

GM_77
04-27-2010, 4:55 PM
Sounds like a magazine problem if the regular 10 rounder was working.

Is it a brand new PMAG?

Check the feed lip of the 10/30 to see if it is broken. One test is to fully load the 10/30 and give it a good wack on the bottom. If a round ejects then the feed lips could be deformed or broken.

Stubby
04-27-2010, 8:07 PM
oh yeah, Welcome to th AR!!!! It can be a temperamental :censored:

IsaacGlass
04-27-2010, 8:31 PM
Just took my new AR (bought off a Calgunner) to the range for the first time and had some serious jamming issues. I think it might have been related to the mags I bought (10/30 PMAG) because it didn't seem to be an issue with the stock 10 rounder. Ultimately the spent casing was not clearing before the bolt came back and dozens empties got smooshed as it tried to close. Advice anyone? Thanks in advance. CMMG lower and upper if that helps.

Get new mags. Where did you buy the 10/30 from?

Pryde
04-27-2010, 8:40 PM
Short stroking or bad extractor.
The mag is probably making the problem worse but from what you describe it doesn't seem like a completely mag-induced issue. Even if the mag is jacked up, the empty should still be extracting at the very least. Most mag failures result in a failure to feed a fresh round.

Check for gas leaks, then check the extractor claw to see if the edges are overly rounded and then check the ejector (the spring loaded cylinder on the bolt face) to see if the spring tension is adequate and if it will go down and retract when you push on it.

anniepoks
04-27-2010, 9:01 PM
oh yeah, Welcome to th AR!!!! It can be a temperamental :censored:

....just like a wife or a GF i say :( .....agree?

JPurp
04-27-2010, 9:42 PM
It sounds like you already diagnosed the problem as the PMAG. For the most part they are flawless but there was a batch the developed a hairline fracture down the back spine. You may be unfortunate enough to have one of those.

Chris89002
04-27-2010, 9:55 PM
I have had the same problem with my C Products mags. The regular 10 rounders shoot fine but the 10/30's do what you say. Although I have not shot my AR enough yet to determine the exact problem. Also, I was using Tula 55 gr. and that may also be the problem. Its some pretty cheap stuff.

bubbapug1
04-27-2010, 9:59 PM
If its short stroking you might want to run a heaveir buffer to slow the bolt down a bit. I run a H1 in one of my ARs which had the same issue.

tacticalcity
04-27-2010, 10:05 PM
Make sure you don't have your bullet button screwed all the way down. Loosen it a few turns. If it is all the way down it may lock the magazine in a position that will not feed properly. Had this happen to me. Once I loosened the bullet button so the magazine could move freely, but not so much I could push the button without a tool, it fed properly.

fairfaxjim
04-27-2010, 10:11 PM
Make sure you don't have your bullet button screwed all the way down. Loosen it a few turns. If it is all the way down it may lock the magazine in a position that will not feed properly. Had this happen to me. Once I loosened the bullet button so the magazine could move freely, but not so much I could push the button without a tool, it fed properly.

THIS! The original design wasn't meant to have the magazine locked in tightly. I had problems with some of the original Prince 50 mag locks, and also with BB's that were too tight. The height of the mag lips can vary -they aren't precision parts - and cause the bolt carrier to bind on the magazine in some cases. Some magazines are just not worth a crap either.

nagorb
04-27-2010, 10:45 PM
Paging AR15barrels Paging AR15barrels.

ar15barrels
04-28-2010, 9:49 AM
It's hard to diagnose specific problems online because some people will miss small details in their explanations.
More mags need to be tried to establish a pattern.