Hi all, I just recently purchased a m&p .40 compact. I took it to the range today and fired 150 rounds through it.

During the shoot, the slide did not reposition itself forward half way through my 10 rounds. I shot 4 bullets through and after the 4th, the slide did not return to position and stayed open as if the magazine was empty. I dont believe this is normal, has anyone else experience this?

Another issue; could be user error. My cousin was shooting the gun and half way through the 10 rounds, the bullet did not go off as if it was a dead round. I ejected the bullet and saw no hammer pin marking on the back of it. I put it back in to the magazine and shot it without a problem. It seemed a bit odd at first but this happened twice during our time at the range. I was thinking he didnt release the trigger fully but he said he did. I think this may just be user error but if anyone else has experienced this please chime in.

thanks all!

New or used gun? Try a different magazine. Check the firing pin.

Yes, is the gun new?

I've bought 4 or 5 guns in the last couple of months from all different manufacturers and one thing I have noticed is some use a LOT of what I call cosmoline. That was a goey waxy type of gunk that the Army coated everything in to prevent rust.

I'm not sure if that's what the manufacturers are using, but when I strip down a brand new weapon I clean a lot of gunk off it! Even my M&P, which comes with a fired round, left me with a pile of dirty patches. I cleaned a new Ruger rifle and I swear I could have used a putty knife to scrape off all the goo...

Anyway, a dirty gun can malfunction.

Not having enough info to tell if there is a problem, most likely the gun is fine. Maybe ammo, maybe technique... or just a little clean and oil... I can tell you I have 4 M&P's.. last one I bought was a 40c last week. Threw a new Apex sear and spring at it, couple of drops of oil on the slide and ran 100 rounds through it last monday.. flawless. Haven't seen any of the cosmolene type stuff on any of these, but am sure it was more common years ago.. let us know what up... dirty barrel from the factory is normal I think.. they don't seem to clean em after the test firing.

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Jack C

It was a used gun that was in very good condition. Looked almost brand new. I even cleaned it before taking it to the range making sure everything is lubed. There was very little dirt when i cleaned it. The ammo I used were Federals if that makes a difference.

the thing that bothered me the most was the slide not returning back to position when there were still rounds to be fired in the magazine. Im planning on going back to the range soon and see if it happens again.

Too much oil?

You can try it with no oil at all and see what happens.
Otherwise send it back to Smith and have it repaired.

Had a similar problem with my40c last fall.No failures to fire but the slide would not go back to full battery on occasion.Posted that issue here and some of these fine intelligent gentlemen suggested to check if it only occurred with a particular magazine.Embarrased that I didn't think of that on my next range trip I paid more attention.Well guess what,those guys were right.Problem only arose on one mag.Performance was flawless with the other magazine.Went home and disassembled that one and found what I will call paint flakes caked on the spring and inside walls of the mag.Cleaned her up and not a hiccup since.My problem started somewhere around500 rounds if I remember correctly(which I probably don't).Somewhere over a thousand now with no more problems.