M & P AR Jamming.....

[millbilly]

I have a new M & P flat top in 223 and it seems to hate steel cased 223 ammo.....like wolf of brown bear......anybody else having this trouble ? They will feed and fire then not eject and the bolt will lock up with the empty case in the chamber......you have to break open the rifle and pry the bolt open to get the case out......seems to be OK with Remington or Winchester ammo.

 

[Bob R]

Is the steel cased ammo coated with lacquer? I know the newer stuff isn't supposed to have the laquer coating.

The other problem could be a carbon buildup in the chamber. Wolf (or any steel) ammo does not expand enough when fired to seal the chamber so you get a little bit of carbon between the case and the chamber. If you get enough of it extraction and ejection becomes very difficult.


That is one of the reasons I only shoot brass in my AR, or any gun I like. That, plus the fact I am always leary of Russian ammo being corrosive, no matter what they say.

But, that is just me.

bob

 

[tom turner]

A word to the wise . . .

NEVER break in a new rifle with that cheap Russian steel cased ammo. It is rough on the rifle.

Instead, run about 300-400 rounds of quality brass cartridges through your new AR15 first. This will smooth out the action perfectly, and then the rifle will digest anything and everything you feed it, steel-wise . . . as long as it is manufactured correctly and to spec.

AR's don't need much breaking in:

1. Brass only for a few hundred rounds to smooth out the action . . .

and

2. Keep the bolt and action oiled and wet.

T.

BTW, Wal-Mart is selling Federal .223 in 55 grain with brass cases for $39.97 per 100. That's not TOO bad, cost wise vs. running that cheap Russian stuff through it during the break in period.

You've spent a lot for a truly fine rifle. Spend a little more to break in the action and you'll be good to go in the future with the Wolf or other steel cased 5.56 ammo!

 

[millbilly]

I will stick to just GOOD ammo.....Thanks.....Where do you live ? Our wal-mart has been out of ammo for weeks in central Ill........

 

[tom turner]

Hi,

They are usually out in my town too. So, I swing by a few times a week. Usually Tuesday afternoon is a winner here.

Try to get on the good side of your Wal-Mart gun person and maybe he/she can set you a box or two aside.

After the break in period of 300-400 rounds, you'll have no trouble at all with the harder steel case stuff . . . but right now feed it soft brass and the gun will be more reliable for it in the long and short run.

This is true for any AR-15 make. And keep 'em wet!

Enjoy!

Tom

 

[w9kcj]

Millbilly ,
Try Farm & Fleet
http://www.farmandfleet.com/stores/illinois.aspx

Norm

 

[tom turner]

Hi again, millbilly,

Please let us know how your carbine did with some good ol' brass ammo once you get to take it out to shoot it again.

Hopefully it will be crappin' out the spent rounds like a goose!

T.

 

[millbilly]

Farm and Fleet had a sale on Remington 223.....$7.99 box......I have a rain check....they sold out quick, Went by wal-mart Friday morning after work,,,,They had just put 20 boxs of 9mm (100 rd) winchester $21 a box....I called all my buds and told them....I don't have a 9 mm or I would have bought some...still seemed like a good price.....It was all gone by 10 am.......still no 223...

 

[S/W - Lifer]

ARs need at least 5 things to run well - reliable mags, breaking in, cleaning when needed, lube and good ammo. MilSpec ammo is the best and if you are not familiar, that refers to quality, not a brand.

 

[Doug M.]

Have the chamber specs checked with a 5.56X45 gauge. My guess is that like most commercial ARs, the chamber is not within specs. You may need to find a reamer, like Ned Christiansen's. Go to the SWAT magazine web page and look for the article he did a few months ago.

You may also have an extractor tension issue - make sure it has the correct (black) o-ring, etc.

 

[MTKTM]

An experience I had a few years back was with a fairly high-end AR that I purchased from J-P Enterprises. It was a fairly specialized IPSC 3-gun piece and had a "match" barrel. John Paul told me to use only US made ammo, said that foreign stuff and especially the steel-case Soviet bloc junk would not function well in the tight chamber. I followed his advice although did use some old manufacture PMC brass ammo just to see whether it worked. He was right, it didn't. Newer PMC is fine, however.

My guess is that you've got a 'snug' chamber and that the cheaper ammo is slightly oversized. PMC works and is generally a little less expensive.....when you can find it.

 

[cbpotel]

Don't run the gun dry, it will jam and cause all typed of stoppages. Lubrication cures a multitude of sins.

 

[Raven6]

millbilly,

I teach AR-15/M-16 courses for a living, as well as armorer's courses, mainly to law enforcement agencys and their officers. The first thing I tell ALL students is that you should never feed steel cased ammo through any weapon that is a member of the AR-15/M-16 family.

Steel cases with lacquer coating tend to gum up the chamber, be it chrome lined or not. This gumming up of the chamber causes it to be harder to extract the spent round, while at the same time dangerously increasing the chamber pressure since the case is not being extacted in the timely manner for which the system was designed. You will run into the same problem with non-lacquer coated cases, but it will take longer to show up. Steel does not have the same lubricity as does brass. It causes problems.

Not all lacquer coated steel case ammo comes from China or Russia. I have had law enforcement officers come to the range with department purchased ammo that was from Hornady - and it was steel cased, lacquer coated.

Of course, this is just my opinion. But... My opinion is based upon 24 years of instructor experience and from test results that came from the Aberdeen Proving Grounds.

You've got a good weapon there, and you paid not a small sum of money for it I'm sure. Don't feed your thoroughbred table scraps. Feed it good quality food and keep it healthy.

Regards,
Mike

 

[MTKTM]

ARs with 'minimum' or 'match' spec chambers will quite often not function with the commie steel-cased stuff. In fact, some won't do very well with brass foreign ammo. Even PMC can, at times, be sticky in a tight chamber.

I have two Armalite ARs, one is a National Match and the other a more mil-spec carbine. The former has a tight chamber, the latter seems able to digest just about anything. I've not measured either, but this is my assumption based on performance. I'd guess that the S&W has a snug chamber and would not shoot the steel stuff, not now, not ever, through it.

 

[n4zov]

You have a quality firearm and using quality ammunition is just common sense IMHO. Shooting the cheapest ammo available through a good rifle is the equivalent of using the cheapest motor oil you can buy in a nice new car.

 

[Noah Zark]

I have five ARs, and they each either prefer or hate steel cased ammo, be it lacquered, polymer coated, or zinc-plated "Silver Bear:"

Colt 20" HBAR Sporter Target preban -- HATES STEEL

Bushmaster 16" "M4gery" -- HATES STEEL

S&W M&P15, Stag built early model -- LOVES STEEL

S&W M&P15, S&W-built late model -- HATES STEEL

Short Barreled Rifle I built on a Sabre Defence lower/used 10.5" Colt upper -- LOVES STEEL

All of the above uppers are stamped "5.56mm", yet there is variation between the guns as to whether steel cased ammo functions or not.

Originally posted by Raven6:
Steel cases with lacquer coating tend to gum up the chamber, be it chrome lined or not. This gumming up of the chamber causes it to be harder to extract the spent round, while at the same time dangerously increasing the chamber pressure since the case is not being extacted in the timely manner for which the system was designed. You will run into the same problem with non-lacquer coated cases, but it will take longer to show up. Steel does not have the same lubricity as does brass.

I'm not sure you wrote what you meant to write, Raven. No AR15/M16 will extract a fired case until the bullet is past the gas port and gas is channeled to the carrier/bolt through the gas tube. Case material has nothing to do with "increasing chamber pressure to dangerous levels."

Steel is less elastic than brass, and will grip the chamber tighter and for a longer period of time due to steel's inability to "relax" after the pressure drops to atmospheric, thus requiring a higher extraction force. Add in sticky lacquer or a buildup of case neck sealant in the far end of the chamber and the forece necessary for extraction overcomes the force of the extractor claw on the case rim, and the next thing you are slamming the rifle butt on the bench stool or ground, or reaching for the cleaning rod and mallet.

After shooting any steel cased ammo, or ammo with neck sealant, I always swab out the chamber with a patch soaked in acetone. Acetone will either dissolve the sealant or shrivel up lacquer deposits into little "chips" that are easily removed with a chamber brush and a few more patches. After that, good to go.

Noah

 

[Tempest 455]

Here is what I found with the steel cased (like Wolf) ammo. It jammed my buddys AR bad. It also jammed a Glock 19 my brother in-law had so bad we barely could extract it from the chamber.

Once I got the round out, I thought maybe the tolerance was off and measured it compared to some Winchester and Remington rounds. What I found was shocking:

The Wolf ammo is all over the map on tolerance. The Winchester, Remington are all the same in diameter. The Wolf 9 mm round that jammed his gun was .012" larger than a Winchester 9 mm round.

I started to measure a few Wolf .223 rounds. I found they were all over the place as well. Worst case (literally) was .007" larger than Winchester.

To date, I only went through 3 boxes of my Wolf .223 and I'm tossing any that are .003" larger than the Winchester/Remington. So far, roughly 27% of the ammo measures "too large" diameter in my opinion. I'll shoot the rest that is close (since it's money already spent) however, probably will not buy anymore Wolf ammo.

 

[Raven6]

Noah Zark: Well, I can see how my statement could be interpreted in a way different from what I intended... I used what my college professor would have called a "comma splice" (and he would have given me an automatic "F" on this post had he reviewed it due to the "comma splice".) Let me try again...

Steel cases with lacquer coating tend to gum up the chamber, be it chrome lined or not. This gumming up of the chamber causes it to be harder to extract the spent round. Measuring from the time the bullet has passed the gas port located beneath the front sight frame and then exited the muzzle: a lacquer coated steel case (that is hard to extract due to the gummed up chamber) will spend more time in the chamber once the round is fired (even though we are talking only micro-seconds) than would a brass case in a chamber that is not gummed up. That period of time, even in micro-seconds, is enough to increase chamber pressures to dangerous levels.

Regarding lubricity... Steel does not have the lubricity of brass, thus brass is used in bearing material more often than steel. Likewise with ammunition, steel is more likely to grip and wear against a steel chamber than is brass.

In reality, we are making the same point, only approaching it differently and maybe using different words.

Regards,
Mike

 

[millbilly]

Havent been on the forum for awile......Just an update....cleaned and oiled my M&P shot remington 223 ammo (55gr) and all my feeding trouble has gone away........Also bought a Stag model 6 and shot the same ammo in it with no issues......I really like the two stage target trigger on the Stag.....think I'll get one for my Smith.....Thanks for all the valuable info

 

[Vulcan Bob]

I ran some of the Russian steel cased stuff out of my Savage Tactical bolt gun. Some would chamber ok some would require varying degrees of effort on the bolt from light to very hard. The recoil and report varied greatly as well and accuracy was dismall. This told me that this ammo suffered from poor quality control and convinced me never to fire this kind of ammo out of any of my AR's. Also have heard its hard on extractors in the AR but have no first hand experiance on that subject.