M&P45c: Problems returning to battery

[Palmguy]

I've had this gun for about 2 weeks now, FDE M&P45c...and have 108 trouble free rounds through it. When dry-firing (or when performing a press-check as that is virtually what I'm doing all the time when dry-firing), unless I walk the slide all the way forward, it wants to catch and not return completely to battery, as shown in my crappy pic here:

http://i134.photobucket.com/albums/q116/bridoyal/100_1957.jpg

This does not occur whatsoever when firing, so I'm not extremely concerned about it...but it does seem unusual to me. I can put my thumb on the back of the slide and it will go all the way forward. I dry-fire with a single snap-cap in the chamber and an empty mag in the gun, but the problem doesn't seem to occur without the snap cap.

Neither of my other M&Ps exhibit this behavior (M&P9 and another 45c, this one black with no safety). Swapping the top ends of the 45s seems to remove the problem with both the FDE's frame and original slide (i.e. with the slides swapped, neither gun has the problem).

When removing/reinstalling the slide on the FDE, the rails/locking block seems pretty snug. It's slightly more difficult to get the slide on or off of the frame on the FDE gun.

Thoughts?

[Semi_auto]

I had the exact same problem with a 1st gen Glock 17. Turned out to be a weak recoil spring.

[John_Wayne777]

I think you've already identified your problem: The snap cap. Snap caps can get damaged or deformed especially if they are cycled into the chamber from a magazine (which is the right way to do it) several times. On some of the metal snap caps the deformation can cause any number of issues like you are experiencing.

If you aren't having issues feeding live ammo you don't have anything to worry about.

[Palmguy]

I think you've already identified your problem: The snap cap. Snap caps can get damaged or deformed especially if they are cycled into the chamber from a magazine (which is the right way to do it) several times. On some of the metal snap caps the deformation can cause any number of issues like you are experiencing.

If you aren't having issues feeding live ammo you don't have anything to worry about.

It's only that gun though. Same snap cap doesn't give me problems in the other M&P45c.

Also, I can replicate the problem with any live .45ACP round I have here (Blazer FMJ, Hornady TAP, Gold Dot, Golden Sabre...). I guess it just doesn't present itself with live ammo unless I were to press-check.

Like I said, I'm not real concerned about it, it just seems odd to me. I guess it could be a weak recoil spring....although the other gun works fine and the FDE gun still does it with the black gun's recoil spring.

Not a big deal I guess...thanks for the posts guys.

[Vinh]

My 4" M&P45 did the same thing when brand new. Went away within the first 300 rounds.

[Palmguy]

My 4" M&P45 did the same thing when brand new. Went away within the first 300 rounds.

Good to hear. Thanks.

[ToddG]

Probably just a function of the gun being on the tight end of the tolerance. I'd expect it to work itself out with use, and as JW777 pointed out if it's not happening during the normal firing cycle it's nothing to worry about.