AR Failure To Feed Problem


I have this AR (.223 Wylde) that I put together five or six years ago. Previously, it's always ran really really well. Unfortunately (after a couple other AR builds) It's been sitting in the safe for a couple of years and I finally took it out a couple of days ago (I should have cleaned it first before going out) and went to the range. It ran really sluggish since it was really gunked up (I think the last time I cleaned was with frog lube which really sucks if you're going to keep a firearm stored for a long time).
So, I cleaned it up really well including taking bolt carrier group apart and cleaning it up really well. Yesterday, I went back to the range and it ran a lot smoother, but about every few rounds I would get a failure to feed. I would either get the kind where the bolt would not pick up a round at all, then have to pull the charging handle a couple times to pick up a round or the kind where the round would not fully enter the chamber (which is even more frustrating if you are not paying attention and try to pull the charging handle again and get an attempted double feed). I only took two magazines with me. One was just some generic 5.56 magazine and the other was a HexMag.
What should I look for? What can I do to try to fix failure to feed issues?

Just because people are going to ask, here are some photos...






Once you verify its not a weak magazine spring here are the steps I would take.

The very first step I take is swapping out the bolt carrier group. If you have another BCG from a different rifle try swapping it out. If the swapped BCG feeds then it could be your extractor on the original BCG. It will need to be replaced.

If the replacement BCG does not work try replacing the buffer spring with a new buffer spring.

If that doesnt work there is an issue with either your gas block or your tube. Make sure the gas block is aligned correctly. If it is try replacing the gas tube.


Failure to feed can be frustrating! 9 times out of 10 it can be resolved two ways:

1: clean the rifle. Like really clean. Then add a thin coat of CLP

2: bad magazines or hand on magazine. Switch out the magazine to either s USGI or Magpul. Then be sure to not touch the magazine or rest it on the bench when firing. Outside manipulation can change the mag angle and mess with feeding


As already mentioned, Start with the easy stuff and work up.

Full cleaning
Use a known G2G mag, one that's fed another rifle, I prefer pmags
Cycle the magazine manually through a full round, confirming functionality

Check gas system, alignment, check for rare blockage

Check/replace buffer spring

Eliminate any other variables if possible, use recently purchased, reputable manufacturer ammo, make sure mag isn't getting pressure at an odd angle from your positioning, etc.


I gave it a run again on Sunday. I used a new PMag, same problem. Swapped out the BCG from a rifle that has no issues and still had the same issue. So, what I am going to do next is replace the buffer and spring. If that doesn't work, I'll drop in a new lower parts kit (at least the bolt catch and magazine catch).
I gave it a run again on Sunday. I used a new PMag, same problem. Swapped out the BCG from a rifle that has no issues and still had the same issue. So, what I am going to do next is replace the buffer and spring. If that doesn't work, I'll drop in a new lower parts kit (at least the bolt catch and magazine catch).
What ammo are you using ?
I gave it a run again on Sunday. I used a new PMag, same problem. Swapped out the BCG from a rifle that has no issues and still had the same issue. So, what I am going to do next is replace the buffer and spring. If that doesn't work, I'll drop in a new lower parts kit (at least the bolt catch and magazine catch).
This has nothing to do with your lower parts kit.

The buffer and spring did not wear out if they previously worked fine with the same ammo. Is it just a standard carbine spring and buffer or something fancy?

How is the gas block attached? Set screws? Dimpled barrel? Most likely that's where your issue is, in my opinion. The screws backed out, or the barrel wasn't dimpled and the gas block shifted. I would verify that the gas block is properly secured and aligned before spending any money on replacement parts. Also make sure your gas key is properly attached.
In the picture of your upper it looks like there are burrs on the feed ramps. Is that just my imagination? Check the feed ramps for any burrs that might catch on the case and impede feeding. If there are burrs they need to be polished out with kratex. Look up School of the American Rifle on YouTube. He has some excellent videos on diagnosing and repairing the AR platform.
In the pic, the bolt and the front of the carrier looks like it has grease with embedded particles in it.
No grease, oil, oil, lots of oil.
Have you used a real chamber brush to make sure its clean.
Failure to strip a round sounds like a mag issue.
As good as they are, P-mags are still plastic, and if they are left loaded over time the feed lips can "cold flow" and distort.
Failure to strip a round sounds like a mag issue.
1) He bought a new Pmag and although a better mag would have been one of the "family" (NHMTG, Okay, Colt) I'm ruling out mags.

2) This could very well be an "under-gassed" issue as astutely mentioned above.
Check your Gas System (gas block, gas tube, gas key)

3) For some reason the OP does not identify his ammo.
So for all we know, he's shooting weak .223 or weak Russian steel.

Above, I recommended full power 5.56 (Lake City XM193 or M855) but no response.

He reported that the rifle previously ran OK.
What we don't know is for how many rounds it was run and we know nothing about previous ammo or current ammo.
For those of you hung up on ammo. I have tried several. American Eagle, Remington, Winchester white box and Fiocchi.
Still not enough information.
Is this .223 or what ?

If so, I would run some full power 5.56 through it as mentioned above.

1) .223 Wylde chamber can safely run 5.56 ammo

2) Why run full power 5.56 in my new-ish rifle ?
To see if it will run.
If it won't run good Lake City 5.56 then you don't have an ammo problem.

As it stands now, you may have a new-ish rifle that is still a little tight and .223 ammo isn't enough to run it reliably until it loosens up.

It's ammo or your gas system.
You break in with full power ammo.
.223 is not full power ammo.
After reading your first post and if you checked all the common problems then it's time to look at uncommon problems. You put it away for years dirty with nothing but frog lube I would clean out or replace the gas tube. you may have had carbon build up that is gunked up with frog lube if lube got into the tube and it hardened over time. Also could be a hardened build up around between the gas port and gas block holes. Also check to see if the gas tube is going into the key with no hang ups.

There are many issues that can cause this but based on it being a working rifle at one time and possibly stored dirty.

2 weeks ago put together a upper and it had problem it was a brand new build. Problem was similar to your but I don't think it's the same problem. The carrier and key are NiB and its funny that I had read and responded to a post about NiB parts where a member noted that the keys tend to loosen up unless properly staked and since this was a new build and I was just test firing it, I had not did that but when I build I really tighten them though. It got gradually worse double feeds failure to feed eventually the bolt would get stuck and I had to pry with a screw driver I visually inspected it and thought I had a misaligned gas tube even though visually it was perfect I thought because there was some difficulty getting the tube through the nut of FF tube that there was vertical misalignment maybe due to a out of spec nut ( it was an off brand FF rail) but it go worse to a point of being a single shot. When I got home and pulled the BCG out I noticed that the gas key was really loose really loose It was not visually loose the 2 times I inspected it at the range but now it was so loose I could wiggle it. I also noticed that the gas tube was not sliding into the key nice and smooth as it did on other BCG so sanded the part that goes into the key a little as well as rolled up a piece of sandpaper and sanded the inside of the key port till it would slide into it smoothly.

I tighten it down but staked it this time and put another 90 rds through without a single hangup.
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