AR-15 Failure to feed issues

Check those things mentioned by taliv. In my book, 500 rounds doesn't even come close to qualifying as "sometime."

Make sure its lubed and it doesn't need to be clean. Does it happen with multiple mags? Did you try different ammo?

ratt_finkel said:

The range guy said the BCG looked a little dry. I just have a hard time believing it's just because of that. I'm not sure why I didn't try a different mag. I was kinda of in a hurry I guess since I had another rifle to shoot and pistols also.

Anyway, the rifle has less than 1k rounds down the tube. It's an A3? style Bushmaster Carbine from the early 2000's. Never had a single malfunction. Always use high quality ammo. Never any reloads.

When releasing the charging handle you could feel the BCG just cease to a halt. Almost like it was getting hung up on the mag (newer tapco). I'll try to take some pics shortly.

Click to expand...

believe it or not, dirty un-lubed bolts and bolt carriers will cause the rifle to malfunction. They like to be run wet.

I've never had good experiences with Tapco mags - try PMags or even GI steel or aluminum mags.

Captains1911 said:

believe it or not, dirty un-lubed bolts and bolt carriers will cause the rifle to malfunction. They like to be run wet.

Click to expand...

I had a FTF with my AR and it was because I wasn't using enough lubrication.
The gun only had about 50 rounds through it and it was jammed to the point that the round had to be "pursuaded" out! I learned that ARs don't like to run lightly lubed! They run best when they are almost dripping!

Yep, lube it generously. If its still causing jams or FTFeed, then there's something else causing the failure.

I guess I'm the exception then. I don't run mine dripping wet. Just a quick spray of remoil on the moving parts and I let it go. I know for a fact the gun has seen over 500 rounds between cleanings/lube, and sometimes that's all in the span of a couple weeks. I can't recall a single issue in any of my ARs that have been run this way, shooting everything from the cheapest steel-cased surplus to my own handloads.


Something's causing it to malfunction, and lube would be last on my list of things to check.


I'd start with the mags. Then check the feed ramps. Then check the bcg. Then check the lower receiver internals. The problem's bound to turn up in one of those areas.

You do NOT lube an AR to a point where it is dripping wet, nor do you lube liberally. If your AR needs to be dripping wet to run properly, you are treating a symptom and not the problem.

To the OP. Does the bolt operate properly when the magazine is removed? With knowing nothing other than the fact that you were using a Tapco mag, my knee jerk reaction would be that it's the mag.

As for the mag catch, I would imagine that if it had broken off, the mag wouldn't have stayed seated. If a part of the bolt release had broken off, that may have caused a problem, but it's hard to tell without seeing it, at least.

Read this for AR-15 lubrication guidance.

Run it wet. Oil on the bolt and carrier should be thick enough to be spread around with a finger. Drop or two into the carrier key. ARs will run wet and dirty just fine.

I vividly remember nearly every single one of the hundreds upon hundreds of pushups with our rifles resting on our knuckles that my BCT unit had to do whenever one of us recruits (we weren't soldiers yet) over-lubed his or her rifle.

Those M-16's would see hundreds of rounds per DAY - and if we used more than a few drops of oil in/on the BCG, we'd be pushing the ground for 5 minutes every quarter mile of the formation run back to the barracks from the firing ranges.

believe it or not, dirty un-lubed bolts and bolt carriers will cause the rifle to malfunction. They like to be run wet.
__________________

Click to expand...

Bingo, I will never understand how the myth begin that you don't need to clean and lube automatic firearms,any machine and an auto gun is a machine
need to be cleaned and lubed,dirt wears & breaks parts.

A clean gun is a happy gun.

I think that the term "wet" is subject to some interpretation. Running a rifle dry means running it with no lube. I'll agree that this is bad. I believe the term "wet" to mean that a rifle should be properly lubricated, not dripping with lube.

What I sometimes wonder about is how clean does an AR have to be to keep running. As of this last weekend, my AR now has over 6K rounds through it since it's last cleaning, although I do lube it every 500 rounds or so, with Slip 2000. I am going to have to clean it soon, though. It's about time for a maintenance inspection.

The only time My H-Bar ever miss fired was due to cheap 30rd. mags.

Bingo, I will never understand how the myth begin that you don't need to clean and lube automatic firearms,any machine and an auto gun is a machine need to be cleaned and lubed,dirt wears & breaks parts.

Click to expand...

The military is always fighting the last war. Every Vietnam Veteran I met was taught to run their weapons dry. This must have come out of the Korea Conflict. From books I read , in the extreme cold conditions of Korea, anything with lube was freezing up. It could not have come out of WW2 as Soldiers were taught to grease their Garands in hot/wet, though there were cautions about running totally dry in arctic conditions. Post Vietnam, the dogma became that weapons must be run totally dry.

When you look at the mechanism, direct impingement blows so much residue back into the action you want lubricant washing/absorbing as much of that off as possible.

In so far as the OP's problem, he needs to try with a different magazine. AR15 magazines are the greatest source of unreliability in that weapon. Once you start getting a pattern of mis feeds from a magazine, it is time to junk that and find another.

I noticed that the mag catch? had broken off.

Click to expand...

You need to correct this to start. The most common AR stoppages are caused by MEAL. Mags, Extractor, Ammo, Lube.

Get some quality Mags, usgi or Pmags. Give the tapco's away.

I run my gas rings wet, a little Tetra grease on the bolt rails and the rest is pretty much dry. Five drops of oil should lube the rifle.

Another vote for fixing the mag catch first (and it's very easy). If the mag is too far in the mag well or not far enough in, either way could cause a FTFeed. If you have a broken part, it is just good practice to fix that before you start treating symptoms.

You mention that the round would not slide into the chamber; why not? If you point the muzzle down, a cartridge should simply drop into an empty chamber. If not, you need to check that chamber for carbon or an obstruction. Once a round drops in freely, you should be able to push the bolt release and have the bolt close completely on the round.

TonyAngel said:

I think that the term "wet" is subject to some interpretation. Running a rifle dry means running it with no lube. I'll agree that this is bad. I believe the term "wet" to mean that a rifle should be properly lubricated, not dripping with lube.

What I sometimes wonder about is how clean does an AR have to be to keep running. As of this last weekend, my AR now has over 6K rounds through it since it's last cleaning, although I do lube it every 500 rounds or so, with Slip 2000. I am going to have to clean it soon, though. It's about time for a maintenance inspection.

Click to expand...

They don't have to be clean at all to function, just well lubricated, and dripping wet is better than dry. Google "Fithy 14", it's a mid-length BCM rifle used by Pat Roger's company that last i heard was over 40,000 rounds, and has NEVER been cleaned, just lubricated.

Captains1911 said:

They don't have to be clean at all to function, just well lubricated, and dripping wet is better than dry. Google "Fithy 14", it's a mid-length BCM rifle used by Pat Roger's company that last i heard was over 40,000 rounds, and has NEVER been cleaned, just lubricated.

Click to expand...

If you look at Pat's 40K rifle you well see he lubes the inside of the BCG and the rest is relatively dry. You want the piston/gas ring area wet, that's all. The oil spray from this when fired well lube the rest.

Watch some of his video, funny guy.

Here is an AR-15 troubleshooting guide that I put together for the armorers course I teach. It is a fairly comprehensive list of possible problems and solutions. Sorry for the long post.

Zero bolt movement when round discharges:

Missing gas tube roll pin
Upside down gas tube
Missing or broken buffer tube retainer
Obstruction in buffer tube

Bolt short cycles when shot:

Leaking gas key
Bad gas rings
Leaking gas block
Recoil spring is too strong
Wrong type of buffer installed
Too many rounds in the magazine
Action is not oiled enough
Gas tube roll pin is missing
Gas block is not properly oriented
Carbon buildup causing sluggish movement
Bad ammunition

Rifle does not feed right when shot:

Too many rounds in the magazine
Magazine is not properly seated in lower
Weak magazine spring
Rifle may not have M-4 feed ramps
Check for home gunsmithing of feed ramps


Rifle does not lock open after last round:

Weak magazine spring
Damaged follower
Bad ammunition (low pressure= cycle failure)
Magazine is not fully seated
Damaged bolt catch
Carbon buildup around bolt catch


Rifle does not fire when trigger is pulled (Click but no bang):

Broken firing pin tip
Carbon on back of firing pin = less protrusion
Weak hammer spring
Excessive headspace
Bad ammunition (faulty primer)
Missing firing pin
Bolt is out of battery (check for bolt bounce)


Rifle double fires or string fires:

Improperly adjusted adjustable trigger
Worn out military trigger
Home gunsmithing stoning job
Missing trigger spring
Missing or worn disconnector
Carbon build up on firing pin


Round is jammed under charging handle:

Worn magazine feed lips
Worn magazine spring


Rifle double feeds when shot:

Bad magazine
Broken extractor
Worn extractor spring
Carbon in chamber


Trigger won’t move when pulled:

Obstruction underneath (primer or rock)
Safety selector is engaged
Bolt is locked open

Round doesn’t extract when shot:

Broken extractor
Worn extractor spring
Dirty or corroded ammunition
Case head separation
Carbon in chamber
Lacquer coated ammunition


Round does not fully chamber:

Dirty or corroded ammunition
Improperly sized reloads
Tight headspace (check proper bolt fit)
Carbon in chamber

Bullets keyholing on target:

Improper bullet weight to rifle twist ratio
Check for rifling in barrel

Magazine inadvertently drops out of rifle:

Improperly seated magazine
Broken or faulty magazine catch
Ambidextrous magazine catch
Worn out polymer magazine
Bargain quality polymer magazine

Extractor breaks frequently:

Discontinue use of steel case ammunition

Bolt is frozen half way back:

Buffer is lodged in buffer tube
Check for rough machining of buffer tube

Rifle won’t hit broad side of barn:

Optic is not properly sighted in
Poor quality ammunition
Check for proper ammunition caliber
Operator error, contact local instructor for training

Magazines and Ammo are always my first suspects.

Insufficient Lube, not so much, especially in a broken-in rifle, but some basic first maintenance is where I'd start before I even looked at mags and ammo. Strip it, check it, lube it.

madcratebuilder said:

You need to correct this to start. The most common AR stoppages are caused by MEAL. Mags, Extractor, Ammo, Lube.

Get some quality Mags, usgi or Pmags. Give the tapco's away.

I run my gas rings wet, a little Tetra grease on the bolt rails and the rest is pretty much dry. Five drops of oil should lube the rifle.

Click to expand...

This says it all. An AR needs to be lubed, but it only needs it in a few key places. The entire BCG does not need to be "wet'.