AR-15 reliability

[Jerkstore]

A few months ago, I bought a Smith & Wesson M&P Sport 2. It was my first serious gun. (I've since bought other guns including another AR-15.) It was technically used, but the store owner said that the gun looked almost brand new and might never have been shot. At the range, I immediately noticed some problems with it in terms of extraction and misfeeds. I was told by an employee at the range that the problem is probably just that it was in the break-in period. So I was patient. Now, a few months later, it's had about 600 rounds through it, but the misfeeds persist. Today it misfed 4 times out of 100 rounds shot. After leaving the range today, I I took it to a gunsmith, and he test-fired it in the shop and wrote on the invoice, "Failures to feed and lock back with 223, weak ejection with both 5.56 & 223 about 5-530." So he's going to try to fix it. This is somewhat frustrating because it is a brand-new-ish gun from a reliable company. I'm wondering if this problem is just bad luck or is it due to the gun being a less expensive model. I don't think I need a lot of fancy features, I just want a reliable gun. How reliable are basic AR-15's like the one I have versus more expensive AR-15 in your opinion?

 

[Hartkopf]

What magazines are you using? Did you number the mags to see if the problem is just one magazine?

I’ve found cheap ARs usually run any ammo all day long. Magazines can be a problem though.

 

[C-grunt]

A properly built AR15 will be very reliable.

It's really hard to disgnose issues over the internet, but it sounds like you might have a gas leak somewhere. With the gun being used, you don't know what the previous owner did to it before trading it in to the gun store.

 

[js8588]

A properly built AR15 will be very reliable.

It's really hard to disgnose issues over the internet, but it sounds like you might have a gas leak somewhere. With the gun being used, you don't know what the previous owner did to it before trading it in to the gun store.

This was my thought too. Misaligned gas block or loose gas key.

 

[gotboostvr]

Worst case scenario, the gas port is slightly undersized.

Best case, the gas block just needs realigned.

Provided the magazines are good, although extraction issues and failure to lock back typically aren't magazine related.

Playing with buffers and springs might be a band aid solution.

 

[trackskippy]

Simple solution is call S&W. They will send you a label and take care of it.

Might take them a couple of times (both times I sent something back to them it took 3 tries), but they will fix it, or give you a new gun.

 

[armoredman]

Smith should take care of that. I've had brand new ARs from PSA work great and homebuilt ones built out of cast offs and leftovers work great - that one is my primary AR. The tech is so mature after all this time that even inexpensive ARs are usually very reliable. The ONLY problem I had was a misalinged front sight block on one upper, (factory fixed it VERY fast), and a bad disconnector in my home built - swapped it out and we were off to the races.

 

[Charlie98]

At the range, I immediately noticed some problems with it in terms of extraction and misfeeds.

What... exactly... was it doing? 'extraction and misfeeds' can mean a lot of different things.

FWIW, and assuming your gunsmith is AR savvy, have him go through the entire weapon... checking things like gas block alignment and security, barrel nut torque, and if things like the ejector and extractor are proper. Just because it's an inexpensive model, doesn't mean it can't be reliable.

I have a DPMS Oracle... a more budget AR than even the M&P... and while it was reliable, the accuracy wasn't that good. I finally pulled it apart... and found the barrel nut was hand tight from the factory. Nothing is perfect...

 

[Hokkmike]

AR's to me seem finicky and like thoroughbreds somewhat demanding.

 

[Buzznrose]

AR's to me seem finicky and like thoroughbreds somewhat demanding.

Not if you buy decent stuff, which generally means a good manufacturer, not econo-gun or Fred’s home budget build…

 

[trackskippy]

I haven't found them to be finicky at all, and thats been across the board $$ wise.

Luckily, 1911 syndrome hasnt bled into the AR's.

 

[gotboostvr]

AR's to me seem finicky and like thoroughbreds somewhat demanding.

I've had quiet a few AR's with no issues. The few times I did, it was a simple fix/adjustment.

I think the number of threads trying to diagnose problems is more a function of just how freaking many AR's are in circulation now.

It seems when AK's have problems, they're rarely easily solved. Trunion, reciever or bolt issue, are not as easy to fix as reseating a gas block, or tightening a barrel nut. Maybe replacing an extractor or buffer/spring.

 

[kwb377]

I've had quiet a few AR's with no issues. The few times I did, it was a simple fix/adjustment.

Same here...I've owned/been issued numerous AR platform rifles...some of them with 15k + rounds through them. I can count the number of issues I've had that weren't magazine related on one finger...and the cause of that was lack of lubrication after @ 1500 rounds.

How reliable are basic AR-15's like the one I have versus more expensive AR-15 in your opinion?

I have three M&P Sport II's (one for me and two sons) and they've been as reliable as any of my personal/work guns (Colt, LMT, S&W, Ruger, Bushmaster)...100%.

 

[IndianaBoy]

AR's to me seem finicky and like thoroughbreds somewhat demanding.

Mine have all been boringly reliable including some race guns with the gas turned down as low as it will go and still lock back on an empty mag.

 

[45/30-06OKIE]

A few months ago, I bought a Smith & Wesson M&P Sport 2. It was my first serious gun. (I've since bought other guns including another AR-15.) It was technically used, but the store owner said that the gun looked almost brand new and might never have been shot. At the range, I immediately noticed some problems with it in terms of extraction and misfeeds. I was told by an employee at the range that the problem is probably just that it was in the break-in period. So I was patient. Now, a few months later, it's had about 600 rounds through it, but the misfeeds persist. Today it misfed 4 times out of 100 rounds shot. After leaving the range today, I I took it to a gunsmith, and he test-fired it in the shop and wrote on the invoice, "Failures to feed and lock back with 223, weak ejection with both 5.56 & 223 about 5-530." So he's going to try to fix it. This is somewhat frustrating because it is a brand-new-ish gun from a reliable company. I'm wondering if this problem is just bad luck or is it due to the gun being a less expensive model. I don't think I need a lot of fancy features, I just want a reliable gun. How reliable are basic AR-15's like the one I have versus more expensive AR-15 in your opinion?

Replace the gas tube first then see what it does. A 20 dollar tube is cheap enough to just pay it and if it doesn't fix it then oh well. My custom AR-10 had a similar issue and a new gas tube fixed it.

 

[Styx]

AR15s are simple and reliable. They typically are only "finicky" and "unreliable" to newbies and those who don't really understand how the platform works. For those who assemble ARs and/or have a good understanding of them, any issue is a matter of a simple fix/adjustment.

Also, AR15s can be and usually are manufactured by many different manufacturers with many different outsourced parts and components and come in many different flavors, features, magazines, gas port sizes, gas lengths, twist rates, dimensions, MILSPEC or proprietary parts, bolt carrier designs, buffer weights and springs, so on and so forth.

The point I'm trying to make in the above is that claiming the entire AR15 platform is "finicky" or "unreliable" based on one or two anecdotal companies' offerings is akin to claiming all revolvers or locked breech striker fired handguns are "finicky" or "unreliable" just because you had issues with a S&W revolver or M&P pistol for one random example.

 

[AlexanderA]

it sounds like you might have a gas leak somewhere.

Or, more likely, some kind of blockage in the gas system. As suggested, you could replace the gas tube (all you need to do is drive out one roll pin in the gas block / front sight tower). Or, clean out the gas tube using a long pipe cleaner. The next degree of difficulty would be to check the gas port. To do this, you would have to remove the gas block / front sight tower.

 

[Styx]

It just might be a case of the gas block being misaligned, the gas key on the bolt not being properly staked, the gas rings aren't good, and as others mentioned, check and clean the gas tube and block which could be the issue.

You said you had another AR15. I'd swap bolt carriers groups (if both of your ARs are in the same caliber) just to exclude there being an issue with the bolt carrier first.

Then being an used AR, it's not known what strength buffer and buffer tube was installed. My guess is the previous owner had issues, and may have made changes to try to fix it.

If I was the OP, I'd simply get a prepaid shipping label and ship it back to S&W so they could fix the issue and insure that it's back to factory configuration free of charge. I'm sure that a lot of what we're suggesting sounds like another language to you right now.

 

[Skeptic13]

I agree that you should send this back to S&W. The M&P is a no frills AR but they are well made and very reliable.

 

[Hokkmike]

AR15s are simple and reliable. They typically are only "finicky" and "unreliable" to newbies and those who don't really understand how the platform works. For those who assemble ARs and/or have a good understanding of them, any issue is a matter of a simple fix/adjustment.

Also, AR15s can be and usually are manufactured by many different manufacturers with many different outsourced parts and components and come in many different flavors, features, magazines, gas port sizes, gas lengths, twist rates, dimensions, MILSPEC or proprietary parts, bolt carrier designs, buffer weights and springs, so on and so forth.

The point I'm trying to make in the above is that claiming the entire AR15 platform is "finicky" or "unreliable" based on one or two anecdotal companies' offerings is akin to claiming all revolvers or locked breech striker fired handguns are "finicky" or "unreliable" just because you had issues with a S&W revolver or M&P pistol for one random example.

Kind of reminds me of the admonition, "If you buy a little English sports car make sure you get a tool set with it - THEN they are reliable." Hey, no I get your point. Especially your second paragraph.You obviously have much more experience with AR's than I do.

 

[d2wing]

If assembled properly from in spec parts, ARs are very reliable and not finicky at all. The problem is many parts makers, quality control and home gunsmithing. Clearly something is wrong and Smith & Wesson should fix it. Or somebody messed with it and it needs to be put in spec. Easily done with an AR unlike almost any other weapon.

 

[Mk-211]

I agree with the other poster about lube and the AR. Properly lubed, AR's like more, will run flawlessly.

I had a gas problem with one, started swapping parts with a friend. Gas key on bolt was loose. Tightened it down and the gun ran prefect. Used punch when I got home and staked it down myself.

Get a can of brake parts cleaner with the straw. Spray it in the gas tube from the chamber end. Do it over a stack of paper towels, watch for any debris.

 

[jmorris]

This is somewhat frustrating because it is a brand-new-ish gun from a reliable company.

Not all “low mileage” firearms are from people that never shot them before they died. Some are problem rifles from the start and are “pawned off” to others vs the often even more frustrating trips back and forth to the manufacturer. Almost new guns and really great deals, I have come to almost expect it. That said, lots of issues have very simple fixes, once you understand how a device works.

 

[drobs]

I've had a couple bad AR15's pass through my hands. The most recent was a Radical Firearms Upper that was a jam-a-matic bought from Primary Arms circa 2012.
Before that was an upper that was sold to me used on Gunbroker as a Bushmaster.

I learned my lesson and only buy new complete uppers / kits from Palmetto State Armory or new complete rifles. All my PSA AR15's (6) have been 100% reliable. My Windham AR15 is also 100% reliable.

I will say, before Covid kicked off I bought 2k of Tula steel case 223 and tried shooting it in 3 different AR15's (a S&W, and 2 PSA AR15's) and instantly got stuck casings where the rim of the cartridge was torn off the very 1st shot out of the magazine requiring a cleaning rod to pop out the broken shell casing. I sold that crap ammo off during Covid.

All other brands of 223 / 5.56 brass and steel case ammo work just fine in all my AR15's except that Tula garbage.

If I were you, I'd get a parts kit with complete upper from Palmetto State Armory and start replacing things on that M&P. Starting with the upper, recoil spring, and buffer.
https://palmettostatearmory.com/ar-15/rifle-kits.html?product_list_order=price_asc

Otherwise ask S&W for a UPS / FedEx call tag.

 

[uuolf]

I've built several really cheap kit ARs... Most worked perfect... And still do... When I did have a problem my first reaction was " what did I do wrong"... Then I disassembled and always found what "I did wrong"... Literally... Both times it was a gas block alignment problem... Most guns that are cheap and reliable are overgassed and run "anything"... they're like a Chevy Vega with a V-8... Push the pedal and it goes... And goes fast... Not perfect but it works... All of mine run anything from min. weight in caliber to max. weight in caliber fine... With no adjustments... That's what I want in case I have to use any kind of ammo in any kind of environment... Look at what COVID did to supply chains.