trouble with polymer mags

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bigoledodge

New member
im experiencing problems with my ar ever since i got it. sometimes wont load next round into chamber. bolt wont pick it up and chamber it. gun is clean so i quit using the el cheapo mags it came with and got a poymer mag. better results but still same problem occurs sometimes. so i clean gun and lube. works fine for a couple clips then same prob. bought a magpul pmag. heard great things about them. same prob. will shoot ten or twenty rounds then not load a few times, shoot a few more then not load. put a colt metal mag in it and shoots flawlessly for forty rounds. are the polymer mags just junk or what? metal mag was a friends so he left. would have liked to ahoot a couple hundred through it with that just to verify thats the prob. so i guess i have made my mind up that i need some good metal mags. what do you guys think?
 
get a Brownell's mag. they are made to strict mil. specs. they actually made several million of them for the military. i have 5 colt mags and 3 Brownell's. no problems
 
What ammo? What rifle? Factory built rifle or home built? There could be alot of problems that make it seem like mag, bolt could be short stroking. Could be an incorrect buffer weight, so many ifs and buts.
 
Originally Posted By: Widow maker 223P mags are usually top notch and cure most feeding problems. +1 on the bolt hold open.

I've never had any problem with P mags at all. I would say having the same problem with several different mags means the mags isn't causing the issue.
 
Is this a built upper? It is very possible to have an upper receiver with M4 cuts and a barrel without M4 cuts. This can hinder feeding from any mag.
 
bolt hold open seems gtg. moves freely unless hammer is not cocked back, then hammer is resting against hold open making it hard to move. is this normal? i prob have not even shot 300 rounds out of this gun yet, possible that its just not nice and broke in yet?
 
I dont think its a mag issue. How do the feed ramps look. Your hammer doesnt touch the bolt hold open. The follower in the mag pushes up on it and holds the bolt back. When u lock bolt back insert mag then hit bolt release, does bolt release move freely, does it load everytime doing this. It could be a short stroking problem but most AR's are over gassed. Is your brass landing. 1-2 o clock or more towards 4-5 o clock when shooting
 
Mine did the same thing but I built mine myself I checked the gas block it's tight it's strait over the hole but I did have a tubbs spring and a spikes heavy buffer in it so I put a plain old spring in it but kept the heavy buffer in hopefully that will cure it if not I'm in the same boat as you. Mine was either not picking up the next round or it would half way load ( round starting up the feed ramp and the bolt jammed halfway up the case.
 
I had the same problem where a fired round would eject and the next round would not be picked up out of the magazine. The bolt would be about 3/4 of an inch from being closed. I tried 5 different magazines and all had the same result.

It turns out the carrier key on the carrier assembly. You know that little doo hickey with the hole in it that engages the gas tube was loose.

It is held in place with 2 screws and then staked but it had come loose. I tightened the screws and applied lock tite. I then peened the screws over and problem solved.

Just one more thing to check.
 
bho is good to go. when i meant hammer was touching, i meant i had the rifle broke open. i shot it this weekend some and it did four rounds then didnt load. cocked it shot 2 rounds then it didnt load. would seem to me that if it were short stroking it wouldnt load any rounds. would it not? dpms wants me to call them. guess i will in the morning. gunshop wanting me to bring it by too lol. will check carrier later tonight. keep ya posted
 
It wouldn't necessarily short stroke every time. My custom build upper took about 500 rounds to break in. It did short stroke a lot until then. I used my original bolt, which I have been told since u shouldn't do. I dunno, but it works fine now. It used to short stroke on every other shot, then less and less as I broke it in.

I didn have any problems with my original DPMS upper. Couldve been the bolt, couldve been the custom upper was tight I dunno. But the long answer to an easy question is it doesn't have to short stroke every time
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when i first started shooting after i got it it did do it alot more often. sometimes it might go through two clips and be fine. but when it acts up it will do it and do it and drive me crazy
 
i would make sure everything is WELL lubed, make sure the buffer isn't dry or binding, make sure all rounds are against the back of the mag and make sure the gas ring gaps aren't aligned. maybe also check the key and the gas tube for alignment or burrs.

good luck hope you get it running like a sewing machine
 
ya its all lubed. rings are good. been told by military friend that the gas rings aliging and causing not to load is myth. anyone else hear that before
 
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