AR-15 Jamming

[GypsmJim]

I know a long way off from S&W, but the clientele here are the most knowledgeable I know of. Asking for my son in TN.

Brand new ATI 5.56 with an oem ATI mag. When the bolt is released on a full mag it extracts a round and chambers it, but the bolt does not close all the way. Trying to pull the bolt back with the jammed round is a real bear.

He bought a different mag of different manufacture and it seemingly worked OK. Conclusion...a mag issue. But then there was a glitch even with the "good" mag.

If the bolt is cocked and release with the release button, it seems to work OK. But, if the bolt handled is pulled back and manually released, some times the same jam occurs.

Anyone have a similar issue?

 

[Eric300]

You gotta pull that charging handle back and let it rip forward all in one quick motion! Don't baby it. From what you described it doesn't sound like a mag issue at all. Make sure the BCG (and even the inside of the upper) is well lubed with a good quality lubricant. Not with your grandaddy's Hoppes oil.

 

[cololab]

The difficulty extracting a round may be indicative of a another issue. Failing to chamber a round fully due to "riding" the charging handle is one thing; difficulty in extracting a chambered round is possibly caused by a dirty chamber, or an oversized round, or an undersized chamber - or all three. Is the rifle perchance chambered in Wylde .223 or 5.56?

 

[erikpolcrack]

Question: When the bolt doesn't quite lock when chambering, does a few slaps on the forward assist close it?

 

[TJm15.38]

I had a similar problem with a Del-Ton 5.56 upper that I put on one of my builds. It would not go into battry with some of my .223 reloads. I had a heck of a time getting the jammed round out of the chamber on the range I took the gun home, did a thorough cleaning of the rifle and the BCG, with special attention to the chamber and the feed ramps. Next time at the range I stuck with Winchester M193 5.56 factory ammo and the thing ran like a champ. I chalk it up to a tight chamber and an upper that demands proper lube. Unlike my AK, the AR requires more cleaning and attention.

 

[Well Armed]

Out of spec ammo or chamber. Could also be that he's riding the bolt home. Could be something else like a weak out of spec buffer spring or sever other possible causes.

I have multiple AR15s, BCG's, uppers, lowers, barrels, charging handles, magazines from different manufacturers, and types of ammo on hand. I can quickly pinpoint the cause of a lot of problems easily by the process of elimination by mixing and matching. It's hard to say exactly what your issue is without having the rifle in hand.

 

[LostintheOzone]

I had a similar problem with a Del-Ton 5.56 upper that I put on one of my builds. It would not go into battry with some of my .223 reloads. I had a heck of a time getting the jammed round out of the chamber on the range I took the gun home, did a thorough cleaning of the rifle and the BCG, with special attention to the chamber and the feed ramps. Next time at the range I stuck with Winchester M193 5.56 factory ammo and the thing ran like a champ. I chalk it up to a tight chamber and an upper that demands proper lube. Unlike my AK, the AR requires more cleaning and attention.

View attachment 696315

That's why the US military went to the the XM7. It truly is more like an AK and every single one of the op rod rifles that came before the AR. The AR is just a dirty rifle.

I've watched people at the range shoot AK's. They aren't the 2 MOA rifles that one can expect with an AR. But they run even when dirty.

You aren't shooting in a match in combat.

 

[kev74]

The first thing I'd try would be a through clean and lube.

Next I'd try different ammo.

If that didn't work, I'd be looking for a set of chamber gauges.

 

[Well Armed]

That's why the US military went to the the XM7. It truly is more like an AK and every single one of the op rod rifles that came before the AR. The AR is just a dirty rifle.

I've watched people at the range shoot AK's. They aren't the 2 MOA rifles that one can expect with an AR. But they run even when dirty.

You aren't shooting in a match in combat.

DI AR15s that are property QC'd and tuned run just fine and are battle ready. Just like with AR15s and even the plethora of semiauto handguns from various manufacturers, AKs can be just as unreliable and problematic depending on the manufacturer and design.

 

[TJm15.38]

That's why the US military went to the the XM7. It truly is more like an AK and every single one of the op rod rifles that came before the AR. The AR is just a dirty rifle.

I've watched people at the range shoot AK's. They aren't the 2 MOA rifles that one can expect with an AR. But they run even when dirty.

You aren't shooting in a match in combat.

You are right. My Arsenal (Saiga) AK clone eats anything I feed it. I don't need to to do meticulous cleaning to make it function. It will never be a match rifle, but it is absolutely reliable even if it's dirty or thrown in the mud. That is what has made the Kalashinkov design famous for the most reliable rifle in the world.

 

[Well Armed]

You are right. My Arsenal (Saiga) AK clone eats anything I feed it. I don't need to to do meticulous cleaning to make it function. It will never be a match rifle, but it is absolutely reliable even if it's dirty or thrown in the mud. That is what has made the Kalashinkov design famous for the most reliable rifle in the world.

What about a PSA, Century Arms, IO inc, and plenty of others? Are they also reliable just because they're AK47s?

Just like Glock clones can be patterned after Glocks, but still be hit or miss depending on the manufacturer. Just like 1911s can be hit or miss reliability wise depending on the manufacturer. Just like striker fired pistols can be hit or miss depending on who makes it. AR15s and AK47s are in the same boat....

 

[TJm15.38]

What about a PSA, Century Arms, IO inc, and plenty of others? Are they also reliable just because they're AK47s?

I can't speak for PSA AKs because I have never owned one. Mine is an Arsenal build with a Russian stamped receiver and Russian internals. The stock and magazine are US-made to make the weapon compliant for import and sale. However, I believe the design of the AK-47 in most any import or form makes it a more reliable rifle in rough field conditions. Look at the videos from Ukraine; their rifles are being subjected to the harshest conditions and they continue to function.

 

[Well Armed]

I own 5 Russian made Vepr AKs that were made in the same factory (Molot factory) by the same company who manufactures AKs for the Russian military. They are now banned from importation thanks to Trump. I also own 2 Wasr 10s and 4 Zastava Npaps (2 Npap DF(s), an M92, and an M85).

That said, there are plenty of AR manufacturers plus AR15s that I've assembled that I'd trust with my life. The majority of the regular hardcore fanboy members on the AKFiles.com forum would also go with an AR15 in a SHTF/WROL situation if they had to choose, and most of them forgot as much as I know about AKs. I can more easily diagnose, fix, replace, etc. parts to keep an AR15 running within many tools or gauges, unlike with AKs....

 

[Shotguncoach]

OP - you didn't mention what brand of ammo was being used. Factory or reload? Brass or steel case?

You also mentioned that the issue happens with a full magazine. Has your son tried it with a partially loaded mag?

Here are the troubleshooting steps that I would use:

- Buy some Federal or Winchester M193 or M855 ammo. Preferably from the Lake City plant. Winchester has the current contract, Federal had it previously.

- Buy a couple of GI spec aluminum 30 round magazines with green followers like the ones from Palmetto. Another alternative would be 20 round mags from Okay Industries if you can find them.

For the following, make sure that there is no loaded ammo in the same room. Check to verify that the rifle is unloaded, then:

- Separate the upper assembly from the lower assembly and remove the bolt carrier group and charging handle

- Scrub the bore and chamber with a brass brush and solvent, then patch it clean.

- Disassemble the bolt carrier group and clean it thoroughly, making sure that the extractor is able to move and snap over the rim of the cartridge being fed.

- Install only the charging handle in the upper and make sure it moves freely. Fit as needed, always changing cheapest part (the handle) if it's necessary to remove material.

- Install the charging handle and the empty carrier and repeat the above test, making sure that everything moves freely.

- Reassemble the bolt carrier assembly using CLP lubricant and repeat the above test. It's normal to have to push the bolt carrier assembly just a bit (one finger) to close the bolt the last quarter inch or so.

- Reassemble the rifle and slather the CLP onto the carrier and charging handle. Don't use so much that it gets into the chamber, but you want the carrier to actually be wet...not just lubed a little bit. You won't run it this way forever. This is just to test and possibly help break in a "tight" rifle.

- As you assemble the upper and lower, make sure that the rear of the carrier pushes the buffer into the stock just a little bit as it closes. The only time the buffer should contact the buffer retaining pin is when the upper is hinged open.

- Verify that the bolt carrier group and charging handle move freely in the assembled rifle. Remember that if you ease the bolt forward it may not close all the way (that last little finger push from above). Try it gently by riding the charging handle forward and make sure it feels the same way it did when the upper was off the rifle. Then test it by locking the bolt open and letting is slam shut under spring pressure, both from releasing the bolt hold open and by a slingshot motion on the charging handle. It won't hurt the rifle to do this a few times.

- If everything has passed so far, insert an EMPTY magazine (remember, there's no ammo in the room) and make sure that the bolt will close over the empty magazine. You'll have to depress the bolt hold-open latch to do this. Do this test both gently (riding the charging handle) and letting it slam using spring pressure.

- If you haven't found the problem by now, it's time to go to the range. Lock the bolt open, load 1 round of Lake City ammo in your GI spec aluminum magazine, insert the mag into the rifle, and hit the bolt release. Did it chamber? If yes, take aim and fire the round. If it jams, take a bunch of pictures through the ejection port and post them here.

- Repeat the test with 10 rounds in the magazine, then with 20 rounds, then 25, then 28, 29, and 30. You don't have to fire every round every time unless you want to, but fire a minimum of 3 rounds each time. If the problem comes back, take note of exactly how many rounds were in the magazine, take a bunch of pictures of the jam through the ejection port, and come back so we can talk more.

- If the good ammo and GI spec mags work, repeat the shooting test with the good ammo in the questionable magazine and with the original ammo in the good magazine. Then go back to the original combination and test that again.

Good note taking and lots of pictures are important for long distance diagnosis. If possible, have your son join the forum so that he can post here and take away one leg of the relay. It may take multiple trips to the range and several posts here, but we'll get your son through it.

 

[GypsmJim]

OP - you didn't mention what brand of ammo was being used. Factory or reload? Brass or steel case?

You also mentioned that the issue happens with a full magazine. Has your son tried it with a partially loaded mag?

Here are the troubleshooting steps that I would use:

- Buy some Federal or Winchester M193 or M855 ammo. Preferably from the Lake City plant. Winchester has the current contract, Federal had it previously.

- Buy a couple of GI spec aluminum 30 round magazines with green followers like the ones from Palmetto. Another alternative would be 20 round mags from Okay Industries if you can find them.

For the following, make sure that there is no loaded ammo in the same room. Check to verify that the rifle is unloaded, then:

- Separate the upper assembly from the lower assembly and remove the bolt carrier group and charging handle

- Scrub the bore and chamber with a brass brush and solvent, then patch it clean.

- Disassemble the bolt carrier group and clean it thoroughly, making sure that the extractor is able to move and snap over the rim of the cartridge being fed.

- Install only the charging handle in the upper and make sure it moves freely. Fit as needed, always changing cheapest part (the handle) if it's necessary to remove material.

- Install the charging handle and the empty carrier and repeat the above test, making sure that everything moves freely.

- Reassemble the bolt carrier assembly using CLP lubricant and repeat the above test. It's normal to have to push the bolt carrier assembly just a bit (one finger) to close the bolt the last quarter inch or so.

- Reassemble the rifle and slather the CLP onto the carrier and charging handle. Don't use so much that it gets into the chamber, but you want the carrier to actually be wet...not just lubed a little bit. You won't run it this way forever. This is just to test and possibly help break in a "tight" rifle.

- As you assemble the upper and lower, make sure that the rear of the carrier pushes the buffer into the stock just a little bit as it closes. The only time the buffer should contact the buffer retaining pin is when the upper is hinged open.

- Verify that the bolt carrier group and charging handle move freely in the assembled rifle. Remember that if you ease the bolt forward it may not close all the way (that last little finger push from above). Try it gently by riding the charging handle forward and make sure it feels the same way it did when the upper was off the rifle. Then test it by locking the bolt open and letting is slam shut under spring pressure, both from releasing the bolt hold open and by a slingshot motion on the charging handle. It won't hurt the rifle to do this a few times.

- If everything has passed so far, insert an EMPTY magazine (remember, there's no ammo in the room) and make sure that the bolt will close over the empty magazine. You'll have to depress the bolt hold-open latch to do this. Do this test both gently (riding the charging handle) and letting it slam using spring pressure.

- If you haven't found the problem by now, it's time to go to the range. Lock the bolt open, load 1 round of Lake City ammo in your GI spec aluminum magazine, insert the mag into the rifle, and hit the bolt release. Did it chamber? If yes, take aim and fire the round. If it jams, take a bunch of pictures through the ejection port and post them here.

- Repeat the test with 10 rounds in the magazine, then with 20 rounds, then 25, then 28, 29, and 30. You don't have to fire every round every time unless you want to, but fire a minimum of 3 rounds each time. If the problem comes back, take note of exactly how many rounds were in the magazine, take a bunch of pictures of the jam through the ejection port, and come back so we can talk more.

- If the good ammo and GI spec mags work, repeat the shooting test with the good ammo in the questionable magazine and with the original ammo in the good magazine. Then go back to the original combination and test that again.

Good note taking and lots of pictures are important for long distance diagnosis. If possible, have your son join the forum so that he can post here and take away one leg of the relay. It may take multiple trips to the range and several posts here, but we'll get your son through it.

WOW. That's the info I was looking for.

It was factory brass 55gr ammo. We also tried it with only 2 or 3 rounds in the mag. We did do some minor oiling, but now we will do a disassemble and do it more thoroughly.

Based on my own experience with my ARs, I suspected that dropping the bolt manually was part of the problem. It DID work ok when using the bolt release button. Also, I suspected that a little more break-in was required.

The original magazine would never work, while the new one did work after our initial oiling.

Thanks again for your detailed follow-up.

 

[H Richard]

One last thing, what ammo are you using? There is a difference between .223 and 5.56. A tight chamber and an untrimmed case can cause numerous chambering and extraction problems. Do you know your chamber spec's?

 

[GypsmJim]

One last thing, what ammo are you using? There is a difference between .223 and 5.56. A tight chamber and an untrimmed case can cause numerous chambering and extraction problems. Do you know your chamber spec's?

I don't know the specs other than the receiver was marked "5.56". The ammo was labeled .223 and it was in a bulk pack. 55gr FMJ and brass cased. It was new, not reman.

Another note is that this was the fir st time the rifle was used.

 

[stanmerrell]

I had a similar experience with my cousins AR15. Turns out the ammo he had bought were improperly sized reloads that would not chamber well. Took me an hour to figure this out. Thought I had the problem solved with correct ammo, and it turned back up less frequently. Gave it a good cleaning and replaced the extractor and extractor spring. That solved it forever. Runs good now. I figure the extractor got damaged with the improperly resized rounds since you had to be pretty rough on it to get a round to clear the chamber. Autos can be finicky.

 

[bobsguns]

Another note is that this was the fir st time the rifle was used.

I bet the bolt carrier group was dry as a bone.

AR's run best when soaked with oil. No such thing as too much oil, the excess will sling off.

My .o2

 

[AManWearingAHat]

That's why the US military went to the the XM7. It truly is more like an AK and every single one of the op rod rifles that came before the AR. The AR is just a dirty rifle.

I've watched people at the range shoot AK's. They aren't the 2 MOA rifles that one can expect with an AR. But they run even when dirty.

You aren't shooting in a match in combat.

You're just parroting decades old myths that have been long disproven. The AR out performs the AK in dirty environments

MUD: AKM vs AR15 - YouTube

https://youtu.be/9APzYqwXckw

Most of the gas used to cycle the weapon is vented out the ports in the bolt out of the ejection port which carries most of the fouling with it. Last paper I read when the Army teste mean rounds between stoppages for the M4 it was 5000+. More rounds than your average serviceman well ever put down the barrel during his contract. This is a paper from the early GWOT era. The guys who operate machinegun ranges in Las Vegas report 20,000 rounds of barrel life with no maker listed, bolts begin to let go around then too. AK's reported to crack at around 100k rounds, have yet to crack a set of AR-15 receivers

High round count AR/M4's (over 100,000 rounds) and how they have handled on our range - Page 1 - AR15.COM

Read away to your hearts content. The AK is an inferior rifle in weight, accuracy, reliability, and build quality and its time to put this mythos to rest. Just ask the Ukrainians fighting with them now.
Guns of Ukraine archive - tons of pics - AR15.COM

The AR-15 platform is highly refined, highly tuned, and extremely reliable and combat accurate to longer ranges than the AK platform to cap it off. The rifle is also significantly easier to service as one who has built a dozen and done armorer service on 10 times as many.

The military is going to the XM7 just like they were going to 6.8SPC in the early GWOT period. It's some generals pet procurement project. The M4 and 5.56 isn't going anywhere. You're right, you're not in a shooting match in combat. So carry more, lighter rounds with a combat effective range that matches that of your average infantryman's skill and put it in a lightweight rifle. We did this optimization a long time ago, and got the 5.56 and the AR-15 platform which excels at its role.

Rounds per infantryman > Individual effectiveness. Logistics > Ballistics.