S&S M&P 15 won't fire

[Danxyz53]

I bought a Smith & Wesson M&P 15 last week. This is my first semiautomatic rifle. I went to the range today and the gun would not fire. The magazine was loading properly and a round was in the chamber after loading. When I pulled the trigger, I can hear a click, but the gun did not fire. After the “dry fire” I was unable to put the safety into the safe position. I ejected the magazine and use the loading arm to eject the unfired round. There were couple of other guys firing AR 15 type guns and I went over and had them take a look. They did not see anything out of line.

Since purchasing the gun, I have broken it down into the upper and lower parts and remove the charging arm and bolt. The gun does have a firing pin. I guess there's either something seriously wrong with firing mechanism or I somehow reassemble things improperly.

Any of you experts out there willing to help the rookie–it will be much appreciated. The firing range is 100 mile round trip from the house, so it was pretty disappointing go there and not be able to use the gun.

[10-96]

Well, I'll take a whack at it.

When you take your bolt/bolt carrier out (as a single unit all put together)- can you push/rotate the bolt into the carrier and push in on the firing pin and see the pin protrude through the firing pin hole?

Or, turn the bolt/bolt carrier group straight up and down with the bolt on top and shake it. Does the firing pin fall out?

These two things could suggest either a short or bad firing pin, burr in the firing pin hole, or simply that it had not been properly assembled.

[rickdavis81]

The safety won't go on after you pull the trigger. It has to be cocked. Did your primer have an indentation where the firing pin hit it? Did you disassemble the bolt or just remove it? Handloads or factory ammo? What kind if factory? Gun new or new to you? Did it fire at all or was it shooting then misfire on the one round? It could be an ammo problem or it could be a gun malfunction. Hard to tell without more info. Post some more details and I'm sure we can help you figure it out.

[Danxyz53]

It is brand new gun, purchased from a local dealer. I removed the bolt and charging arm, but did not disassemble anything else. The ammo was bought at the gun dealer, PMC Bronze .223. The gun failed to fire on the first attempt and never did fire. I ejected the chambered round, reinserted the magazine and chambered a round about 4 times with the same result- no firing. A couple of the rounds show a very faint impressions on the primer. When I remove the bolt, I can push the firing pin forward and see it protrude through the forward end of the bolt, it protrudes < 1 mm.

[ammo.crafter]

Could be a head space problem if the firing pin and firing pin spring are not defective.
I would exchange the weapon with the dealer and have the dealer play with S&W.
You could always contact S&W under the warrenty, but why go thru that hassle.

[DnPRK]

My guess is the bolt is not fully locking into battery.

New AR bolt carrier groups need lots and lots of lube until the rough parkerized surfaces burnish down. It also helps to put a small dab of grease on the backs of the bolt lugs. A properly lubed AR should spit lube for the first couple shots. You might need to pull the BCG every 20-30 rounds a re-lube until you have fired a total of 200-250 rounds. Once everything is broken in/loosened up, you can reduce the amount of lube.

[10-96]

When you chamber a round, do you: Lock the bolt to the rear, Insert a magazine, Push the Bolt Release Button (letting the bolt slam forward), Flip down the Safety Lever, and attempt to fire? Or, do you RIDE the bolt forward with the charging handle to chamber a round?

I'm not trying to insult you, your rifle, or your savvy, but I have seen folks try to be gentle and ride the bolt forward. That can cause your above mentioned problems.

As DnPRK said- lube the heck out of it. And, even at home, lock the bolt back without the magazine and no ammo, and let it slam home several times and dry fire it A LOT. This will not hurt your rifle. After 50 times or so, detail strip the bolt (keep owners manual handy), re-lube and do it a few more times.

Man, I feel for ya. As far as you are from your range- and with the $$ spent on your rifle, the darn thing ought to work right! Can the folks you bought it from exchange it?

[Danxyz53]

10-96

No offense taken- I am a newbie and not too proud to ask for help. I was inserting the magazine, pulling the charging handle back and easing the handle forward. The bolt was not slamming home.

I lubed the bolt and worked the (unloaded of course) action about 50 times and will repeat again tonight. I did a lot of duck hunting as a kid in south Louisiana, but haven't shot much in 30 years. I'll probably try to fire again in the backyard Monday afternoon- My house is in a semi-rural area with 2-5 acre lots and few 2 ft shots into the ground won't "trigger" a SWAT team.

Thanks to all for the input. If the gun doesn't fire Monday afternoon- it is going back to the dealer.

[10-96]

Hope it clears up for ya. Seriously, letting the bolt slam home and dry-firing won't hurt a thing. We ran drills on doing just that for hours and days on end in basic training before we even saw a loaded round.

I'm thinking that by letting the bolt ride (slowly) forward, you were getting the round stripped out of the magazine and shoved into the chamber, but not enough force was present to push the extractor up over the rim of the cartridge.

Speaking of the old Basic Training days... Try this: When you're letting the bolt slam forward, place a dime or dime sized washer on the barrel just behind the flash suppressor, then squeeze the trigger. We called this "Washer Drills". If you can get in the habit of squeezing the trigger without dropping the dime/washer- that teaches good (or tolerable) trigger control. The idea is that if you're jerking or slapping the trigger, or being unsteady, the dime/washer will fall off. We did this in the prone position till we were blue in the face and flat out sick of washers and dimes... THEN they made us do it in the standing position!

Good luck!

[James K]

It sounds like the bolt is not locking. Since those guns are all fired at the factory, I doubt there is anything basically wrong with the gun.

Did you completely clean the chamber to make sure there is nothing preventing the rounds from fully chambering. Also, try another brand of ammo; it is rare but sometimes a lot of ammo will be out of spec enough to cause the problems you are encountering.

If the problem continues, have the dealer check the rifle headspace with a GO gauge (not a NO-GO or Field gauge - you are looking for too little headspace, not too much.)

Jim

[Miata Mike]

Dan...how did it go?

I am pretty sure too that letting the bolt slam home will do the trick. I just shot my friends M&P 15 for the first time Saturday and had a ball shooting the 200 yard metal plates at our local range.

A very unusual feeling and sounding gun compared to what I am used to that's for sure, but I liked it. Careful with just shooting it into the ground in the back yard.

[Bartholomew Roberts]

Just let the bolt slam home. My guess is what 10-96 suggested - the combination of a new rifle with not much wear in and gently easing the bolt meant that the bolt didn't completely close, even though it looked like it was closed. If the AR bolt doesn't completely lock, the firing pin will not protrude far enough to detonate the primer. Interested to hear how it goes for you.

[Danxyz53]

I generously lubricated the bolt and loading arm, machined barrel opening, cocked the arm and let the bolt slam home about 100 times. The bolt was not closing completely on the attempts when I eased the bolt closed and completely closed when using the bolt assist button. The bolt fully closed when I let it slam home. It may be my imagination, but the charging arm and bolt seemed to move easier after about 50 openings & closings.

Proof of the pin- the gun fired on the first attempt and fired 2 more rounds as fast as I could pull the trigger. The neighbor’s lawn crew had a big mower running 75 yds away, so I don’t think the noise bothered the neighbors.

Thanks to all for the help- I am sure I will be back for help/suggestion in the future. I am getting back into shooting after a 35 year break-

[DnPRK]

It isn't your imagination. It did get easier to work the bolt carrier group because you've burnished down some of the roughness from the parkerized steel BCG and anodized aluminum receiver.

Glad its working for you.

[10-96]

Woo-Hoo!!! I'm always glad to hear when a shooter is back up and running! I'm glad things worked out for you and just as glad or gladder that it wasn't an expensive fix.
Enjoy Sir!

[Major Beef]

I guess I'm late to the party as OP has already fixed his rifle. I had the same problem at first with my S&W M&P 15 not firing.

There would be a light indentation on the cartridge, but it wouldn't fire. The range master took the BCG out and banged it on the rubber counter lightly a couple of times and it's been problem free since. Don't know what the problem was, and I forgot the ask the guy.

I think it's possible that I was easing the charging handle back. When the range master fired his test shot, he let it slam home, so I did everything that he did and it's been working flawlessly.

[10-96]

While I don't recommend anyone abusing their AR's- my frustrations do climb a tad when I see shooters be overly gentle and tender with them. Let me re-phrase that: I get the frustrateds when one sees the light and has been told they're a durable and robust rifle that has gone through much more rough use and abuse than most any of us could dream up during the amount of time it would take to decide there's absolutely no hope of making MRE coffee even halfway palatable- and STILL baby the things like an antique Leica camera... or something.

[Danxyz53]

Just got back from the range and shot 120 rounds without a failure to fire. I was able to cause a fire failure by letting the bolt ease forward very slowly, but I was trying to reproduce my previous problem.

A couple of guys had a brand new AK-47 in the next station and they had problems with failure to fire. The failure to fire rounds had a faint indention in the primer. I mentioned my problem and solution. They got some oil from another shooter, generously lubed the bolt head and worked the action about 50 times. The gun fired every time after the intervention.

How often should I clean the gun? Every 100, 250, 500 rounds?

[DnPRK]

Success!

Lube it when it starts to malfunction. Once everything is broken in, you can go 1000+ rounds without lube (if your bank account can afford that much ammo on a regular basis).

[AROutdoorSoldier]

Well that depends. Do you have a piston or direct impengement? If you have a piston gun I wouldn't, except for running a few patches down the barrel. With a DI gun I would run it for at least 1000 rounds before wiping it out. AR's do not need to be flawlessly cleaned. Usually wiping them out with a cloth and breakfree is good enough. Remember, you need to break it in. The pieces and parts need to burnish each other before they will work together the way they are designed to. Just keep an eye on it and remember more lube!

[10-96]

I clean mine after every outing. Some may say that's excessive, but it's a hard habit for Vets to break. Besides, who's to say that if you're in a humid environment, have to leave your dirty rifle unattended for an extended amount of time- that it won't cause problems the next time you take it out? If nothing else, I would at least clean the bolt and chamber after every trip. How else are you going to familiarize yourself with the innards of the rifle and be able to check for excessive wear, damage, loose gas key, aligned ring slots? Plus, cleaning a "kinda" dirty rifle is a whole lot easier than cleaning one that was let go until it had a stoppage.

But hey, it's really your choice. Guys that let them run till they slow down or stop altogether seem to be OK with that. If you want to let it go without cleaning- be sure to take a cleaning kit and a carbon scraper to the range with you. Having your range trip cut short because your rifle found it's non-cleaned round limit kinda sucks.