Curse the AR-15!!

[tmackay3302]

I went shooting today with my dad's colt AR-15 and it would jamb every 3-6 rounds. It seemed like the ammo wouldn't feed. It's an old gun with old mags and ammo, could any of those be it? Is there anything i can do about it before i take it out on a date tomorrow? Man this is frustrating.:banghead: thanks for your help!

 

[Don't Tread On Me]

1. Clean the rifle, focus on the bolt and carrier. Oil it well. Inspect it for any damage or worn out parts.
   
2. Buy new factory ammo.
   
3. Get a new teflon coated USGI magazine made by D&H with green follower.

If it still jams after that, you'll need to describe the type of jam with the most details possible. This will help to determine if it is an ejection problem, or a feed problem. Feed problems are most often magazine related. Ejection problems are often either the ejector/extractor or a gas problem.

 

[GoRon]

it would jamb every 3-6 rounds. It seemed like the ammo wouldn't feed

So the shell would eject but the new round wouldn't chamber?

Definitely pick up USGI mags and try that as well as making sure it is clean.

 

[Chipperman]

Magazine would be my first suspect.

 

[Gordon]

Put a Wolfe extra power buffer spring in it. It cured my malfs! Something has to push the bolt back and strip off those rounds! While M-4 feed ramps help , of course the Mag improvements do also. Yep run the gun sopping wet with a light oil. Marvel Mystery Oil is real good!

 

[Outsider_10fp]

The mag would be my first guess, and perhaps a dry BGC (bolt carrier group).
Mag spring?
Also, for more info, was it with the mag full, half MT or near empty?
More info please.

 

[Bartholomew Roberts]

Put a Wolfe extra power buffer spring in it.

I'd disagree. Right now we don't have enough information to even figure out what the problem might be. Putting a stronger buffer spring will actually make the problem worse if the problem is not enough gas.

I'd follow Don't Tread's advice and be more specific about when the jam occurs and what it looks like if it continues to be a problem.

 

[RecoilRob]

And, an oft' overlooked tidbit about keeping the gas ring gaps from aligning.

 

[Bartholomew Roberts]

And, an oft' overlooked tidbit about keeping the gas ring gaps from aligning.

Always worth considering if you are having gas problems; but a properly functioning AR will run with a only a single gas ring and having the gaps aligned should cause trouble unless the rifle already has other problems. In that case, having the gaps aligned might be enough to take marginal function to non-function.

 

[possum]

beware, alot of people will say that your problems are caused by the simple reason that it is an ar-15 type weapon no matter what company makes it they all "suck", and therefore it must be garbage, and not worth a dime! but if you want to sell it i'll take it!

 

[geekWithA.45]

My advice:

My guess is that it's just cruddy from lack of use, or has been incorrectly lubed in the past. Mag probs are my second guess.

Clean it. Use gun scrubber or brake cleaner on the bolt, carrier and upper to take it down to "bare metal", and then relube using oil, not grease.

Also check the gas key, make sure it's staked down tightly, and that the whole thing is assembled correctly.

If that doesn't resolve it, there's something else afoot, and it probably won't be solved in time for your date.

Sorry.

and also a good reason to have a spare rifle.

Chicks dig that.

 

[tmackay3302]

Thanks guys. When I looked down the ejection port the bolt was sitting on the back of the new round but wasn't feeding, I would take the mag out put it back in, charge, and it would work fine for a while. just now i cleaned it and oiled it well, so if that's the problem, hopefully it'll be fixed, but i'm thinking it has to do with the mags. the mags are as old as the gun and had been sitting full when we got them, could it be a compressed spring? I'm going out again tonight and will check out the problem closer. I'll let you know what I find. thanks again.

 

[Chipperman]

"mags are as old as the gun and had been sitting full when we got them, could it be a compressed spring?"

I Theenk we have a weener!

 

[odysseus]

May not be the mags - I have heard that people have had mags loaded for sometime and it wasn't the issue. You are able to feed a few. Are all your mags doing this? Are they clean enough?

Assuming all is supposed to be there as mentioned above, if I were you I would break the rifle down for a full cleaning, disassemble the bolt and clean, check buffer and spring in stock, make sure gas tubes and ports are clean enough and not obstructed.

 

[dfaugh]

Curse the AR-15!!

You got it.....




(Sorry but I just had to)

 

[Rexrider]

Try a new USGI mag before doing anything else. This is a logical, simple, and inexpensive first step to take. If the problem persists, then at least you took the magazine out of the equation and we can move on to the next step.

It sounds like the rifle will cycle if a round makes it into the chamber. If you had a gas and/or extraction issue the spent casing would still be in the receiver when it tried to load the next round. It really does sound like a weak mag spring to me. A bad mag will bring the most well tuned firearm to its knees.

 

[Gordon]

After you try the new GI spec mag and clean the bolt and sop it with , oh say Marvel Mystery oil, I repeat put an extra power Wolfe buffer spring(as you might not have access to the milspec spring which IS + power) in for the problem you described! The bolt doesn't have enough ummph to strip the cartridge IF the other things(mainly the mag in this type failure) are straight. I doubt the problem is lack of gas if the bolt is sitting on base of fresh cartridge! The gas is long over by then!

 

[Bartholomew Roberts]

Yes, I might agree with Gordon now. The problem isn't your mag spring (or at least not just that). If your mag spring was weak it would be able to strip the round easily. You have enough friction in the upper that your bolt carrier group is unable to strip a new round. My guess is one of these:

1) Clean and lube the upper per instructions (use a lube made for modern semi-auto weapons (CLP, LSA, FP10, SLIP 2000, etc.) you can use some of the commercial gun oils made for hunting rifles; but they tend to burn off a lot faster if you shoot much - in that case the gun will work fine at first; but slow down with use)

2) Your buffer spring is too weak to strip off a round and push the bolt into battery. Follow Gordon's advice.

Try the cleaning first and see how that works and if you still have issues, do your best to see where it is hanging up, what the ejected cases look like, etc.

 

[Still 2 Many Choices!?]

My(possibly bad) advice,

Clean the buffer tube and spring really good. Oil them. Carbon fouling will choke this area also if it is an old rifle that does not, or has not been cleaned in thousands of rounds. I only say this because the cheapest fix is sometimes the correct one! HTH.

 

[KC&97TA]

check the feed lips on the magazines, they get bent sometimes, that will cause the bolt to not be able to strip off a round and catch.

you can streach the buffer spring, that may work to give it a bit more push

 

[Optical Serenity]

Many times when people come to me (I'm an ar-15 master armorer) with issues like this, I clean the hell out of the gun, and in the process I'll find something to be wrong. Something as simple as a spring or a pin.

And yes, a good magazine is a must with any gun.

 

[Lebben-B]

you can streach the buffer spring, that may work to give it a bit more push

I would not do this. In hand stretching the buffer spring (or any spring for that matter) you run the risk of pulling the spring out of spec. You also weaken the spring even more than it already is by stretching. If the buffer spring is the culprit, then replace the buffer spring.

Mike