Mis-fires with my M&P 9mm

mlehtovaara said:
How cold was it?

My Maverick 88 only ever miss fired with light strikes when it was really cold, and I had over oiled the bolt/firing pin channel.

Possible if it was really cold, and the firing pin channel was full of oil it might have gummed up.

Were the misfires the first few shots after loading a couple mags? Putting your gun down for a couple minutes to reload mags, might have given the oil time to gum up, then once a few shots were fired it was enough to free the firing pin.

Just a thought.
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The temp was about -4C . Misfires were mostly in the first box. Sometimes on the first round sometimes on the 3rd round so no consistancy. There was time between shooting because I had another pistol and my ruger sr22.

The striker channel, spring and striker were quite oily when I took it apart. Cleaned everything up.

Will get back out soon to give it a try. Still trying to find some different 9mm rounds in Halifax area.
 
While I'm betting it's probably the ammunition, I would say check the firing pin and firing pin channel as well. I carry the M&P every day for work and have spent extensive time with it. IF it's not the ammo (which I'm betting it is), it's gotta be the firing pin. Keep in mind the M&P's are not like many other pistols, they're designed to run DRY! If there is lube or oil in the firing pin channel, it can get gunked up VERY quickly. Keep 'em clean
 
matt491 said:
While I'm betting it's probably the ammunition, I would say check the firing pin and firing pin channel as well. I carry the M&P every day for work and have spent extensive time with it. IF it's not the ammo (which I'm betting it is), it's gotta be the firing pin. Keep in mind the M&P's are not like many other pistols, they're designed to run DRY! If there is lube or oil in the firing pin channel, it can get gunked up VERY quickly. Keep 'em clean
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So you work for an armoured car company, wow. That's hardly "extensive" time with an M&P seeing as how you carry it, and don't shoot it daily. I'm with Sinasta, where in the literature does it say to run it dry?

TDC
 
TDC said:
So you work for an armoured car company, wow. That's hardly "extensive" time with an M&P seeing as how you carry it, and don't shoot it daily. I'm with Sinasta, where in the literature does it say to run it dry?

TDC
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I think he was referring to the striker channel.

Do you know this guy and when and how much he shoots?

The M&P's don't require a lot of lube. I don't run my dry but I do just use a very thin coating on the four contact points where the slide contacts the frame. Nothing more. Compared to other designs I would describe the lubrication requirements as being almost dry.;) I don't think there is any need for grease anywhere on this pistol. All grease will do is attract abrasive material like unburned powder and gunk.

To the OP the right hand cartridge looks like it got a good wack with the striker. I am betting ammo related.

Take Care

Bob
 
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IM_Lugger said:
the V shape comes from the pressure of burning powder gasses pushing the primer back into the breech face/ firing pin channel.

The second one looks like a light strike. If your other 9's don't have a problem with that ammo, I'd be checking the firing pin channel for gunk/ excess oil.
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Happen to me with my M&P.

I accidently dropped some oil in the firing pin channel while cleaning. That oil plus the carbon form the first 50 rounds partially blocked the hole therefore my pin could not stick out completely anymore. I had the same "V" shape and light strike mark on the primer.

Clean that hole.

:D
 
I put many many thousands of rounds through M&P's shooting IDPA and IPSC.

As some have mentioned they should be very lightly lubricated only at the lube points indicated in the manual. You should never (also mentioned in the manual) allow oil in the striker channel. It will quickly cause a carbon build up on the forward shoulder of the striker and cause occaisional light strikes.

In sub-zero weather I found it best to fieldstrip the piece and shoot it dry. As long as you are not shooting hundreds of rounds it should be okay.

I believe you have already taken the most important step in stripping and cleaning you gun. If the problem persists I would definitely try different ammo.

Good luck and good shooting :)

M&P's are great little guns.

John
 
Sinasta said:
Show me where S&W says to run it dry or that it was designed to run dry.
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My MP9 manual suggests that one drop of oil in seven spots (so 7 drops in total) is sufficient :) Compared to others - like my 226, which needed to be dunked in a vat of breakfree before use - 7 drops is pretty much dry :cool:
 
Canuck44 said:
I think he was referring to the striker channel.

Do you know this guy and when and how much he shoots?

The M&P's don't require a lot of lube. I don't run my dry but I do just use a very thin coating on the four contact points where the slide contacts the frame. Nothing more. Compared to other designs I would describe the lubrication requirements as being almost dry.;) I don't think there is any need for grease anywhere on this pistol. All grease will do is attract is attract abrasive material like unburned powder and gunk.

To the OP the right hand cartridge looks like it got a good wack with the striker. I am betting ammo related.

Take Care

Bob
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If he's talking about the striker then obviously dry is the correct answer. As for light lubrication, its still lubricated so running it "dry" would be incorrect. As for grease, it does not actively "attract" anything. That being said, even the crap that does end up suspended in the grease(same way it is suspended in oil, if its still present) is hardly going to cause a stoppage. The same light lubrication desired with oil is the same with grease. Except that grease won't drip, burn, or blow off during use... Do we really need to discuss this again???? Please point out the negative aspects of PROPERLY lubricating a firearm with grease?

subneural said:
My MP9 manual suggests that one drop of oil in seven spots (so 7 drops in total) is sufficient :) Compared to others - like my 226, which needed to be dunked in a vat of breakfree before use - 7 drops is pretty much dry :cool:
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Breakfree is a sh*t product and is NOT a lubricant. Its a general purpose liquid mess that gets promoted by ill informed users.

TDC
 
I'm not here to justify myself or tell my life story to internet warriors. No time, and, frankly, I just don't care enough to try and prove myself to anyone here.

As I said before, the firing pin channel is meant to be clear and dry. Keep it that way. That'd be the first thing I'd check.
And personally, while not 100% dry, I consider 7 points of LIGHT lubrication to be much "drier" than 99% of other pistols out there
 
matt491 said:
I'm not here to justify myself or tell my life story to internet warriors. No time, and, frankly, I just don't care enough to try and prove myself to anyone here.

As I said before, the firing pin channel is meant to be clear and dry. Keep it that way. That'd be the first thing I'd check.
And personally, while not 100% dry, I consider 7 points of LIGHT lubrication to be much "drier" than 99% of other pistols out there
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Actually you do need to justify yourself if you're going around telling people that the M&P is designed to be run dry.
 
Sinasta said:
Actually you do need to justify yourself if you're going around telling people that the M&P is designed to be run dry.
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Directly from the manual,
"There are seven (7) lubrication points where a single drop of
high-quality firearms lubricant should be applied. This will ensure
proper lubrication. Care should be taken not to over-lubricate.
Excess lubricant can collect quantities of unburned powder and
carbon residue, which could interfere with proper functioning of
the pistol"

As I said, 7 points of light lubrication, keep the firing pin channel clear and dry! If you want to lube your firing pin channel, that's your call
 
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matt491 said:
Directly from the manual,
"There are seven (7) lubrication points where a single drop of
high-quality firearms lubricant should be applied. This will ensure
proper lubrication. Care should be taken not to over-lubricate.
Excess lubricant can collect quantities of unburned powder and
carbon residue, which could interfere with proper functioning of
the pistol"

As I said, 7 points of light lubrication, keep the firing pin channel clear and dry! If you want to lube your firing pin channel, that's your call
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matt491 said:
Keep in mind the M&P's are not like many other pistols, they're designed to run DRY!
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Unless I misunderstood you and you were trying to say you meant the firing pin channel from the start. But you have yet to correct your statement earlier.

No different than a Glock where the firing pin channel is not suppose to be lubed. So whats your point?
 
Back from range. Tried American Eagle and Winchester 9mm.

Fired 1/2 box of each and no misfires. Also tried 5 rounds of reloads no problem.

Still had problems with the MFS rounds. Finished off the last box and had quite a few misfires. They did finally fire after a couple attempts.

Looks like I will stay away from them even though they work for others.

Not 100 % certain that it is the ammo yet, I will know better with more range time.

kevin

***On another note I am glad I got the range kit with the Maglula Uplula. Sure makes loading the mags a lot easier. I find it very difficult loading them without it.
 
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Hunter850 said:
Back from range. Tried American Eagle and Winchester 9mm.

Fired 1/2 box of each and no misfires. Also tried 5 rounds of reloads no problem.

Still had problems with the MFS rounds. Finished off the last box and had quite a few misfires. They did finally fire after a couple attempts.

Looks like I will stay away from them even though they work for others.

Not 100 % certain that it is the ammo yet, I will know better with more range time.

kevin

***On another note I am glad I got the range kit with the Maglula Uplula. Sure makes loading the mags a lot easier. I find it very difficult loading them without it.
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Certainty can rarely ever be obtained. The evidence you post suggests strongly that your issue was ammo related. Perhaps a bad batch of primers? I would stick with another brand(s) and maybe try some more MFS ammo later in life. If your light strikes re appear then its clearly the ammo.

TDC
 
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