AR15 feed issue. [Archive] - Glock Talk

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Glock19Fan
01-21-2013, 18:48
I got an Olympic Arms AR15 a couple of weeks ago. Ive heard bad things about them, but the deal was just too good to pass up (I traded a $450 firearm for it).

Anyway, I took it to the range today, charged it, fired, and got a feed problem. I took a couple of pictures, but in case you cant see it appears the cartridge got stuck under the bolt rather than being pushed in from of it. It made it only halfway out of the magazine, and was starting to go inside the chamber but got stuck. When extracted, the cartridge case had two large dents on it from the pattern on the bolt.

This was M193 type ammunition, the weapon was detail cleaned before the range, and well oiled.

http://i50.tinypic.com/30uqzhg.jpg
http://i46.tinypic.com/2em3jmq.jpg

Any way I can fix this?

battlin bulldog
01-21-2013, 18:55
What kind of mags where you using and what was the condition of the feed lips? It is most likely a bad magazine.spring/follower/ bent feed lips... And not to sound like an smart*** but was the mag seated all the way. I hope any of these remedy your problem.

Glock19Fan
01-21-2013, 18:57
The is the older "Plinker" model with the cast lower by the way.

Happypuppy
01-21-2013, 18:58
It does look like a mag problem. It looks to me like it tried to feed it and was hung up on the lips for the mag causing the dents.

Glock19Fan
01-21-2013, 19:15
I mayyy have found the problem?

While disassembling it, I looked at the gas rings and it appears one of them is partially missing. These also seem stationary.

http://i46.tinypic.com/5btdm0.jpg

I also took pictures of the rest just in case. The magazine is a pretty newer production Brownells in good condition.

Here is the bolt
http://i49.tinypic.com/og00pc.jpg
Upper
http://i47.tinypic.com/1ieszo.jpg
Lower
http://i45.tinypic.com/tainnc.jpg

Tango 1Zero
01-21-2013, 19:20
Weak ammo?

ah see you may have found it as I was posting.

Glock19Fan
01-21-2013, 19:33
Weak ammo?

ah see you may have found it as I was posting.

I doubt it, this was 5.56 ammo.

I am gonna try to get some new gas rings and replace them to see if that corrects the issue.

Does anyone think bad gas rings would cuase this problem? They are pretty bad and like I said it looks like someone cut a section off one of them.

byf43
01-21-2013, 19:54
I would suspect either the magazine (easy enough to eliminate - use another magazine!), or, check the barrel to receiver fit, specifically the feed ramp(s).

WoodenPlank
01-21-2013, 20:00
The gas rings could definitely be the culprit, especially if one is damaged. Magazine is also a very likely culprit.

Once you replace the gas rings, try loading ONE round into the magazine and fire. Does the bolt lock back? If not, you likely have a gas problem causing short stroking.

Tony Rumore
01-21-2013, 20:22
Your gun is either short stroking for various reasons or the mag is letting the head of the cartridge case sag down in the mag slightly. The bolt is actually catching the cartridge in the groove/rim of the case, not getting behind the case head. When the bolt catches in the groove, it will shove the round out of the magazine but the cartridge will tilt upward enough to allow the bolt to slip out of the groove and run up the case body, leaving that dent.

Glock19Fan
01-21-2013, 22:03
The rings look pretty severely damaged compared to normal ones. I will replace them ASAP and if I have any more problems I will let you guys know!

Thanks guys! :wavey:

Glock19Fan
01-22-2013, 19:13
Well, I replaced the gas rings today and took it to the range. Upon charging it, I automatically got a feed issue. I cleared it, and actually fired 5 rounds in a row without issue. Then the same jam happened again.

I did notice today that the bolt catch doesnt hold the bolt to the rear, although it does engage. Just not enough to hold it. Both with and without a magazine inserted. Would this have anything to do with it?

The magazine seems to be in good condition, but I may try another magazine tomorrow. Other than that I am out of ideas.

Anything else anyone can think of?

mjkeat
01-22-2013, 19:31
I have seen this before but can't remember the remedy though I do know how to avoid it. We won't get into that.

Try a new mag and/or bolt.

This might be the reason for such a great deal.

EDIT: check the bolt lugs

VinnieG
01-22-2013, 19:40
We have had more problems with the brownell mags than any other. I agree with trying a different mag

Glock19Fan
01-22-2013, 19:50
Well, some possibly good news. I placed the upper onto the lower from my other AR15. Bolt locked back perfectly with now problem. So now I think the problem may be in the lower.

Anything to look out for on the lower? Possible buffer tube? I believe the magazine isnt the problem becuase I used it in my M4 with no troubles.

Glock19Fan
01-22-2013, 20:05
Well I may have found this issue. I put my Bushmaster lower and this Oly lower side by size. I noticed that the buffer spring tube on the Oly was about 1" shorter than the Bushmaster. Not only that, but I removed the actual buffer springs, and the Oly had a spring 1" longer than the Bushmaster (Shorter tube + longer spring = more tension?).


What do you guys think about this? Should I try a shorter spring, or were the Olys springs made unusually long?

Glock19Fan
01-22-2013, 20:10
Problem solved (maybe). I took the shorter spring from the Bushmaster and installed in the Oly. I assembled the rifle, charged it, and pushed the lock in and the bolt stayed back.

Now to find a new spring. I looked briefly online but never seen any specific spring measurements. Would it be safe to cut the spring?

vettely
01-22-2013, 20:13
The most common cause of problems is usually magazine related. What happened when you tried several other mags?

Apetrulis01
01-22-2013, 20:32
It could be a few things.

- Wrong buffer
- Bad Magazine
- feed ramps (are they polished / are they m4 feed ramps)

Those are just a few I could think of off the top of my head.

Adam

Glock19Fan
01-22-2013, 21:28
The most common cause of problems is usually magazine related. What happened when you tried several other mags?

I only used one magazine, but these are the same mags that worked flawlessly in two other weapons.

I could be wrong, but I think a combination of bad gas rings and heavy buffer spring were cuasing the rifle to short stroke. I replaced the gas rings, and I will try to find a carbine spring tomorrow (or attempt to cut it a little shorter?). Hopefully this solves the problem. If nothing else I will take a serious look at the mags, but I am relieved that with the shorter spring from my Bushmaster the bolt was able to lock to the rear.

WoodenPlank
01-22-2013, 21:55
Count the coils on both springs. Length can vary depending on age and use, but coil count will tell you if the spring is wrong.

Glock19Fan
01-22-2013, 22:29
The Oly definately has more coils. If I cant find a carbine spring locally I am gonna take 5-7 coils off it since most online stores are out of stock.

WoodenPlank
01-22-2013, 23:04
The Oly definately has more coils. If I cant find a carbine spring locally I am gonna take 5-7 coils off it since most online stores are out of stock.

How many coils are on each spring?

A standard carbine spring should have 37 could +/- 1 coil depending on how you counted it. A rifle spring has 42, if memory serves correctly. It sounds like you got a rifle spring in your Oly, which will absolutely cause short stroking issues - I learned that from experience.

Glock19Fan
01-23-2013, 00:01
How many coils are on each spring?

A standard carbine spring should have 37 could +/- 1 coil depending on how you counted it. A rifle spring has 42, if memory serves correctly. It sounds like you got a rifle spring in your Oly, which will absolutely cause short stroking issues - I learned that from experience.

You are correct, I counted each one and the Bushmaster had 37 and I think the Oly had 43 (although I could have miscounted from 42). I used a dremel to cut 6 coils off, installed it in the Oly and automatically the bolt was able to stay locked to the rear. Not only that but I hand cycled some rounds through the rifle. While the failure rate wasnt as high, I did have the same type of feed error with the Brownell magazine. So it did have a small part in this but I believe the gas rings and the recoil spring were the main problems. At the very minimum the bolt will now go all the way back.

I loaded a newer 20 round steel magazine and had zero malfunctions with all 20 rounds cycled.

So I am going to go to the range in the morning with multiple mags and see how the rifle does. I am hoping that the problems are finished becuase I like the idea of a $460 AR15.

WoodenPlank
01-23-2013, 00:04
Replace the cut spring with a proper carbine spring as soon as possible.

Glock19Fan
01-23-2013, 00:13
Replace the cut spring with a proper carbine spring as soon as possible.

Ive looked in several places online but without any luck. Ill check locally in the morning but I did bend the end of the spring to avoid a protruding point.

Happypuppy
01-23-2013, 00:21
Call olympia arms or try J&S (jsgunparts.com). He sells a ton of Olympia Arms guns at our local gun shows

Glock19Fan
01-23-2013, 00:27
Call olympia arms or try J&S (jsgunparts.com). He sells a ton of Olympia Arms guns at our local gun shows

When I checked their website they had a note stating they wouldnt have any firearms or parts for several months?

Happypuppy
01-23-2013, 18:48
When I checked their website they had a note stating they wouldnt have any firearms or parts for several months?

Give them a call. They are moving to a bigger location I believe. He maybe able to give you a local contact to get one from if he does not have any

Glock19Fan
01-23-2013, 19:07
Give them a call. They are moving to a bigger location I believe. He maybe able to give you a local contact to get one from if he does not have any

Will do. I test fired today and had zero issues out of 20 rounds, so I know know I am looking for a carbine spring. Im pretty excited to have this figured out

MajorD
01-23-2013, 22:04
Another very common problem is the mag catch being loose. Tightening it several revolutions may help. Always when trouble shooting go for simple first- mags ammo change swap uppers and lowers from other guns before getting into the guts of the gun. It sou ds like you have other ar's I would try that upper on another lower and see what happens. I have been around the ar platform since the mid 1980's and have never replaced a set of gas rings. Doubt that is the problem.

WoodenPlank
01-23-2013, 22:15
Another very common problem is the mag catch being loose. Tightening it several revolutions may help. Always when trouble shooting go for simple first- mags ammo change swap uppers and lowers from other guns before getting into the guts of the gun. It sou ds like you have other ar's I would try that upper on another lower and see what happens. I have been around the ar platform since the mid 1980's and have never replaced a set of gas rings. Doubt that is the problem.

Gas rings wear out over time, and eventually fail. If you haven't had to replace a set, then either you have been very lucky, or you don't shoot very much before selling an upper or BCG.

Glock19Fan
01-24-2013, 02:23
Another very common problem is the mag catch being loose. Tightening it several revolutions may help. Always when trouble shooting go for simple first- mags ammo change swap uppers and lowers from other guns before getting into the guts of the gun. It sou ds like you have other ar's I would try that upper on another lower and see what happens. I have been around the ar platform since the mid 1980's and have never replaced a set of gas rings. Doubt that is the problem.

Look at the picture I posted of the gas rings. Its not that clear, but it is still obvious that the lower gas ring is mostly ripped and missing. The rings wouldnt even spin on their own.

I beleive I mentioned trading uppers and lowers, and always had a problem with whatever the Oly was attached to. The upper on the Bushy lower was just fine.