I recently purchased a M&P 15 Sport. I have had some problems with the gun jamming. I am using the stock pmag and bushmaster 30 round magazines that came with the gun. I am shooting Remington PMC factory .223 ammo purchased from Walmart. I have fired the gun about 80 -100 times. If the bolt and receiver are not well lubricated with Breakfree CLP or Rem oil (or other such lubricant), the gun will jam. Specifically, the gun will lift the cartridge from the magazine but will not push it into the chamber. The cartridge will get caught between the bolt and the chamber. The cartridge case will be well dented near the shoulder so bad the cartridge will have to be discarded. This problem happened about 1 in 3 rounds when the gun was first fired. It now happens about 1 in 8 times. Several shooters of ARs at my gun club have observed this problem with my rifle and tell me the gun just needs to be shot in rather than sent back to Smith and Wesson for repair. The fired cartridge cases have observable scratches on the case necks and the case bodies. I am interested in getting readers opinions and advice. Also, what 3 shot groups are reasonable at 100 yards? Thanks in advance.

You answered your own question right there. AR's function better wet. Lube the bolt , and BCG rails.

Also, the 15-Sport is a tad over gassed. Install an "H" or "H2" buffer and see if it cures your harsh ejection problem.

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-John

Spikes ST-T2 buffer and a blue Sprinco spring. Run it wet.

double post lol

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CLEAR!

Get a heavier buffer when you can....


Oil the cam too

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CLEAR!

Where do your ejected rounds land ?

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Light, Accurate,Versatile M&P

The ejected cases land in a very small area, 3-4 ft diameter circle, about 10 feet from the shooting position. The cases land to the right rear from where I am shooting- at about a 4 o'clock position if the muzzle was at 12 o'clock. I am shooting off a concrete bench rest using a padded blanket over the concrete with the rifle being rested on sandbags for stability.

Where does the bolt come to rest against the cartridge? Behind it, still trying to push it up the ramp, or does it override the base and come to rest against the body of the case?

Is the gas key on your bolt carrier loose?

Is your gas tube loose where it connects to the front sight base?

Is the gas tube off center or not coming back far enough in the upper receiver? Compare with pictures of other ARs on a google image search.

Have you tried a different brand or lot of ammo?

Are all three gas rings present on the bolt? Any deformation or damage?

Any obstructions in the receiver extension, aka buffer tube?


Ignore the "advice" above to get a heavier buffer until you find out the real cause for your malfunction.

I would also add to the above make sure the gas rings are not aligned the gaps should be staggered and spray some lube in the mags as well.

Your buffer spring and ejector are working correctly. Some magazines are not happy feeders until broken in. Some just suck. As to the brass having scratches on the side of it, that is an ejector grabbing and pulling hard on the brass, as is the rim of the cartridge having a dent rather than a scuff.

My personal advice? Get a chamber brush, and slather it with some polishing compound. ( Automotive rubbing cxompound first.) Work the chamber well. Next, use a true polishing compound (Fine rubbing compound) Slather the chamber brushg with it, and again, work the chamber well.
The REASON: Melonite coating is very, very hard. Any machining grooves will be 'proud' after the treatment. Many, many rifgle chambers are not very polished. Of course, when you are manually working the bolt slowly, it is not an issue. This rings true for chrome lining also, but to a much lesser extent. The chrome tends to be slick by nature. If the machining was pretty good, the chrome is usually really slick in the chamber. Most are pretty smooth.
When i polish a chamber, I use a corless drill and chuck a single section of cleaning rod into the drill. I use a boat load of polishing compound, and I go SLOW. I do not spin 'er up and get it done quicker. Bad things happen..... 1/2 speed in low gear is about right. In and out gently, as it spins. You want to clean it up and just smooth out any rough edges inside....NOT polish it to the moon. Clean the chamber well between the 1st and 2nd polishing steps. Clean it well and lube it afterwards.
YES, you can do this with just 1 type of polishing compound. I recommend 2, but that is me.
NEVER use sandpaper in there.
For those who shoot a LOT, this type of extra cleaning will possibly need to be done every once in a while; say every 20,000 rounds or so. If you shoot steel (Wolf, Silver Bear, etc) you will maybe need to do this about every 12,000 or so.
After a polish job, most chambers will never need it again.
My Sport had no issue from the get go, but it did argue after 5,500 rounds. One polish job, and it's golden. 99% Wolf ammo.
My DPMS was just like your rifle at first. After 300 rounds, and some frustration, I polished it. 6,500 later...... still perfect.

Do NOT lube up mags. They will gall inside as they collect powder residue and dust. (Especially plastic type Pmags, etc. They are GREAT right out of the box. Don't ruin them prematurely.)

Just ran across this thread looking for info on S&W turnaround times. I had to send my brand new OR model in for the EXACT problem two weeks ago. I am familiar with the platform, and mine seemed to have the problem with more than 10 rounds in the magazine. I believe deeply that my bolt was coming forward before the magazine could push up the next round. If I spec'd and built the rifle then I would add buffers, etc, but I feel a rifle from the factory should have ZERO malfunctions, so it went back to the the folks who built her. Just hope to get her back soon in full working order. Then I can add my Spikes buffer, and BCM charging handle.

Wow...I just posted the same thing up. Having the same issues. Im thinking it's possible I didn't lube the bcg wet enuff to my rifles liking.

One big thing people miss is initial prep before shooting-

Did you strip and degrease/ clean the rifle before shooting it? Rifles come in a variety of conditions, from packed in grease, to lubed to death, to dry as a sand box, to just right.

Disassemble the bolt assembly, lube the bolt with 2 drops on the wear surface, and 2 drops on the gas rings themselves. Lube the cam pin with a drop or 2 of oil. Oil the glide surfaces, they are the flat slides on the bottom, and top of the front end of the bolt carrier. Oil the charging handle, a drop or 2 will do.
You really will not need more than this. You oil it in this manner, with the oil of your choice. Mobil 1 is good, I use Tetra and Slip, and sometimes RemOil. No heavy oils, no greases of any kind..... too sticky. Catches too much debris and slows down the action.
Dragon and JaPes are pretty spot on with their point on this. ( I DO stress staggering the rings, but the truth is.... if the rifle works reasonably well, the ring position will not detract from performance. On a really finicky, home-brew gun, it can make a difference.

In the end, lube it and shoot it silly. It needs to break in. Good luck! Paul.

AR's like to be run wet. Not dripping, but close.

The alignment of the gas ring gaps doesn't matter at all. Also, lube in the magazines not only collects grime, it can be dangerous. If too much lubricant is transferred to a case body before it chambers, this condition can drastically increase rearward force on the bolt during firing, leading to damage or personal injury.

I am not talking dripping wet. I place a very small amount to help the plastic carriage inside ride smooth especially with a new mag I learned that trick in bootcamp from my senior DI and I haven't had any problems with it either in the Corps or now. You don't use any more lube than what you would spay on a cloth to dust with

I have 4 mags two from s&w and two from colt for the 16 and they all was a little sticky until I did that and after 1200 rounds still no problems with the mags or oil on the rounds.

Here is a interesting article on mags:
Extreme Duty AR-15/M-16 Magazines from D&L Sports, Inc.

Yes unfortunately dated practices in the military build a lot of bad habits about firearms maintenance, and oil in the magazines is just one of them. The gas ring alignment myth is another.

One of my Drill Sergeants in basic told me he put CLP on his ammunition to make sure the rounds fed well. Just because it came out of a DIs mouth doesn't make it good advice.

I agree with you about believing everything out of a DI's mouth lol but in the article I posted I was having the carriage getting cocked on me like in the top left picture and that did stop that problem and it was the same thing in boot camp. But at the same time I do see your point about over lubing especially the dirt and getting excessive oil on the rounds is a big no-no.

Wonder if the practice of oiling the magazines to prevent jams was taught before the introduction of the 'anti-tilt' follower??

Before the ATF was introduced some magazines did have a tendency to allow the rounds to tilt in the magazine causing mis-feeds and a little oil would help alleviate the tilting problem.

These days I just disassemble my mags and wipe the internals down with an oily cloth cuz I ditched the ones that weren't ant-tilt.

The SS magazines I own are Teflon coated on the inside.

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AKA: "Strange Tamer"

Update:

Just picked it up last night from being sent back to Smith & Wesson. Haven't had a chance to shoot it yet but it appears someone has run it through its paces, outside of barrel and gas tube under handguard looks like it got pretty warm and BCG is coated in black residue.... I was actually glad to see this as it seemed to indicate to me at least someone got her to run. Broke it down and cleaned it after I got home to see if I could see evidence of something different as S&W sent no information as to what was done, if anything. The lube on the recoil spring smelled different and the bolt was much smoother in the carrier and of course the black residue were all I could find.

Today I received an e-mail from the store that sent it in for me and was told, "We did in fact send in your gun for repair because of the feed ramp and chamber not aligning. When Smith and Wesson send repaired firearms back to us, they just send and invoice with the Serial Number listed and say that the gun has been repaired to Smith and Wesson’s specifications and if there are any questions to call and inquire."

I plan to shoot it this weekend, hope it works.

Thanks for the informative thread, been a pleasure.
Doc

Oil on the ammo or the chamber is a bad idea.

When the gun is fired, the brass appears to the expanding hot gas to be as soft as rubber. The case expands to obturate and in this process, firmly grips the chamber wall. Oiling the ammo or the chamber means this grip is reduced; the result is an increase in "bolt thrust," which is the case's tendency to push backwards against the bolt face. Increasing bolt thrust puts more stress on the bolt face and locking lugs. Not a good idea.

I agree with Dragon, it's a waste of time trying to stagger the gas rings, where the gaps are doesn't matter. Heck, in a properly functioning AR you can get by with just one gas ring in an emergency.

And I agree you don't put oil in your magazines. The GI mags have a dry lube coating inside and the PMAGs are slick enough as is. Lube the BCG liberally not the mags.

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US Army 1966-69, VFW Member

Gas ring disalignment is still taught during assembly and cleaning in my last 3 duty stations over the past 16 yrs. Though I've read this argument on every major forum.
If this is the case, it's neither rite or wrong.

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Light, Accurate,Versatile M&P

Who is this that's teaching to stagger the gas ring gaps? Probably guys who were told the same thing at their last duty station, and don't know enough to question it.

Align your gas ring gaps and shoot the AR, try to create a malfunction. Let me know when you do. I won't be holding my breath.

directly out of the S & W manual:
Assemble your rifle in the reverse
order that you took it apart.
• Make sure that the gas-rings
on the bolt are NOT aligned
when reassembling. (Figures
64 & 65)
• Lubricate all metal parts by
wiping them with a cloth
dampened with a high quality
firearm oil. Remove excess
oil. Leave a light film of oil on
all metal parts of your rifle -
inside and out.
• See page 29 for details regarding the piston driven variation
and its unique instructions

CATAMs instructors, aka military gunsmiths.
Combat Arms Training And Maintenance.

As Per AF TO/ARMY TM
I will try and find a copy to see if it's still in there.

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Light, Accurate,Versatile M&P

Believe me that's not nearly as impressive as you intended it to be. I've known several military "gunsmiths".

I have emailed S & W and asked them why? I am interested in the response .It should be interesting.

I don't want to cause a argument but here is the reply from smith and wesson.


"The optimum configuration is for non-alignment as the gas is forced in one direction creating greater pressure and velocity.



Aligned the gas will have less pressure and velocity as it will take the path of least resistance.





Have Good Day



Michael"

And you think S&W is the authority on ARs? They are just repeating the same myth, started by the same sources, we've been talking about.

Again, align the gas rings and shoot the thing. Stop believing rumor and test it yourself.

LOL. Well... who IS the authority on AR's? Eugene Stoner? Ruger puts the same instruction in their owners manual. They got in the AR business later than Smith did.

I'm gonna align mine some time and see if it still works.

I hope you aren't expecting Dragon to answer you, since the post is three years old and 99% of the guys who responded are no longer actively participating in the forum.

Glad someone else has noticed that this ol' equine has expired. or at least should have.

don't really actively participate, read a lot, just wanted to say I did have a spot on post on the first page of this thread

Actually, Since this was brought back to the top, I didn't at first notice the date until I got to MY post! But I was thinking, hmmm, this sounds similar to the way my Ruger AR556 started out....

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Rod
M&P 22A, 40c, 15A, 15-22

It seems the more knowledge people have about firearms, the stranger their advice gets to a simple question. Basically if you bought a firearm that has a lifetime warranty, and it doesn't go *BANG* when you pull the trigger, send it back to the manufacturer. You shouldn't be worrying about too much or too little oil, this or that, or anything else brought up. In a SHTF situation the last thing you want is an undependable firearm.
I have a MAC-90 that has never failed me. Not once, no matter how poorly I treat it. I have been shooting it for around 25 years. However, my new S&W Sport II has been garbage so far. It's going back.

Chapter 5
Pg. 56 (5-12)
Step 3.
Figure 17

Lots of good info for all of us. this is a joint pub.

http://www.google.com/m/url?client=m...XVCfcm2skFa5cA

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Light, Accurate,Versatile M&P

Dragon, please don't act as if were on m4carbine.
I posted the spelling for non mil types who are reading.
It was not ment to say or show anything more than what it is.

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Light, Accurate,Versatile M&P

Yeah Dragon LMFAO you should have posted this....




Now That is more like it children!!!!!!

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CLEAR!

What's all the fuss? It's a sport, it's not a real AR, of course it's going to jamb!

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Rod
M&P 22A, 40c, 15A, 15-22

Exactly, it ain't worth the paper the money you paid for it was printed on

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Light, Accurate,Versatile M&P

J/K, I just wanted to post that for the dramatic effect that I was thinking it would have

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Rod
M&P 22A, 40c, 15A, 15-22

I still think the cause of the jams is insufficient lubrication of the BCG.

This indicates to me that the OP ran the Sport on the dry side.

I just read and learned a lot, time for me to clean my bcg and start over with some royal purple in a little one drop at a time bottle. Thanks guys

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Grover Oathkeeper

Ya, I read that whole instruction last night, lots of stuff in there I haven't heard of.

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Light, Accurate,Versatile M&P

I took the M&P15 Sport shooting again yesterday. All shots were from a concrete benchrest covered with a padded blanket and shooting from sandbags and rest. All ammo was Remington UMC 55 gr factory cartridges purchased from Walmart. The bolt was liberally sprayed with Breakfree CLP and the inside of the receiver was liberally wiped with the CLP. Here is my firing procedure. I place a live round in the chamber and close the action by depressing the bolt catch, the bolt "slams home" (safety on). No one else is at the range- I had it to myself yesterday. Next, I load 3-5 rounds in one of the pmags or bushmaster mags that came with the rifle. Then pushing the safety off, the rifle fires perfecly, and a new round usually cycles perfectly from the magazine as the case is ejected. This works about 90% of the time. The other 10% of the time the spent case ejects but a new round does not go completely into the chamber. I will have to then vigorously pull back on the charging handle, often tapping the other side of the charging handle with a no-mar hammer or the end of a gunsmith screwdrive, to remove the cartridge. However if I modify the loading procedure, the gun jams almost every time. Here is how it almost always jams: if I lock the charge handle back, put 3-5 rounds in a magazine, NOT place a round in the chamber, insert the loaded magazine in the lower receiver, then release the bolt catch, the bolt then goes forward, catches the live found from the magazine, and then the jam occurs, almost everytime. I then have to clear the jam by first removing the magazine. Next the jam will have to be cleared by vigorously pulling/jerking on the charging handle, and often having to rap the other side of the charging handle with the no-mar hammer or the end of gunsmith screwdriver to free up the bolt and remove the live round. This live round never gets into the chamber. The case of the removed live round will usually get dented. I have only used the Remington ammo since I cannot find anything else except Tula, and I have serious doubts about that ammo.

I did look for problems with the gas system but that appears fine. Thanks in advance for tips.

It might be worth trying some different ammo. I have had A LOT of FTF and FTE problems with Remmington ammo across multiple calibers. I have never had a FTF or FTE in M&P15-22 except when using Remmington... needless to say I don't buy Remmington ammo anymore.

I hope you get it fixed! Nothing worse than a mulfunctioning weapon. Best of luck!

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The Paper Assassin

The 15-22 is known to be a little bit of a picky eater, especially when compared to a Ruger 10/22 or a Marlin 60.
With the right ammo, they seem to work really well, and few hiccups.

I purchased a new Sport in early October. I was just able to put the first rounds through it over Thanksgiving. Using American Eagle 223 and a Thermold 20 round mag my Sport functioned perfectly regardless of loading technique. No jams. Very accurate-3 of 5 touching at 25 yards with open sights. Empties land at 4:00 about 6 feet back. Very happy with my Sport.

From the problem you describe I suggest sending your Sport and the mag it came with back to S&W for warranty. Your Sport is basically new. At least give them the chance to evaluate it and repair or replace the upper.

My Sport had a cosmetic defect when i received it--the barrel was scratched, maybe when the FSB was installed. I bought the Sport through the Internet and the seller would not exchange. (Good reason to buy from your LGS- shame on me). I explained the problem to S&W and they replaced the entire upper under warranty.

For warranty go through customer service at the S&W website. They pay shipping both ways through FedEx and give you tracking numbers to follow progress both ways. Return delivery is to your door, but the driver needs an adult signature. I had FedEx hold my return at their service center and picked it up from their service center. My warranty return took 4 weeks. I also sent a S&W 686 revolver in for recall once, and that recall turnaround took 10 days. I've had S&W revolvers for
25+ years. Because of my experience with S&W revolvers when I bought an AR I bought a S&W.

Someone put too heavy a buffer in it?

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Rod
M&P 22A, 40c, 15A, 15-22

At this point, I'd call S&W and send it in for warranty diagnostic and repair.

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-John