.40 FS slide closes when a new mag is inserted

[stev32k]

I've had my FS M&P .40 for about a month and recently the slide started closing on its' own when a new magazine is inserted. It does not do it every time, but maybe once or twice out of ten times.

My 9c does not do that and the .40 only started doing it in the past week or so. Is that a problem and is it something I can fix or should it go back to S&W?

P.S. The slide only closes on its' own when the magazine (15 rd) is full. It has never closed by itself when an empty mag is inserted.

 

[Jyezahn]

Most M&P's do this when a full magazine is inserted with force slightly above normal. Not a problem.

 

[Maddmax]

Yes,normal and not a problem. Myself,I like it.

 

[robkarrob]

My bet is when the mag is inserted firmly, the cartridge hits the underside of the slide and slightly raises the slide. The slide lock lever was not fully locked into the slide slot and the cartridge pushing on the bottom of the slide causes the lever to release. With the mag full, the spring is compressed so much that there is little give when pushing down on the top cartridge. It is really not a bad problem, as I usually want the slide closed after inserting a magazine.

Bob

 

[stev32k]

OK, thanks. I was just surprised when it started doing that. Guess I use more force to insert the mags sometimes.

 

[Bikemobile]

Speeds up your combat reloads!

 

[VMaxSplat]

Speeds up your combat reloads!

Oh yeah! I was shooting a match last week with my M&P 40 and had this happen. There were several comments about the fast reload as we were scoring the stage.

 

[vigil617]

I don't have my 40 FS manual in front of me, but I think I recall that it specifically advises against using too much force when inserting the magazine, period. That's to prevent the very result you're seeing. Instead of "popping" with the heel of your palm to the base of the magazine to seat the mag, firm upward pressure until it snaps into place is better, if you want to prevent the slide from moving forward and, thus, chambering that top round and putting the pistol into battery, ready to fire. The key, though, is your awareness of what has happened when the slide moves forward in this manner, and as long as you realize you're "locked and cocked," it's not a problem.

 

[retarmyaviator]

Oh yeah! I was shooting a match last week with my M&P 40 and had this happen. There were several comments about the fast reload as we were scoring the stage.

I use a M&P 9mm Pro in Production and a M&P45 in Limited 10 both do this and I like it if I happen to go into slide lock during a stage.

 

[VMaxSplat]

I use a M&P 9mm Pro in Production and a M&P45 in Limited 10 both do this and I like it if I happen to go into slide lock during a stage.

My only issue is the way I hold the gun (standard IPSC shooter 1911 grip) sometimes the slide won't lock back. If that happens you just have to cycle the slide and rock on after the reload. When the slide does lock back a dry reload can get pretty quick.

 

[Jyezahn]

I don't have my 40 FS manual in front of me, but I think I recall that it specifically advises against using too much force when inserting the magazine, period. That's to prevent the very result you're seeing. Instead of "popping" with the heel of your palm to the base of the magazine to seat the mag, firm upward pressure until it snaps into place is better, if you want to prevent the slide from moving forward and, thus, chambering that top round and putting the pistol into battery, ready to fire. The key, though, is your awareness of what has happened when the slide moves forward in this manner, and as long as you realize you're "locked and cocked," it's not a problem.

You are correct, this warning is indeed in my manual on page 16. Probably more of a CYA type of thing for S&W, but it's there as a warning nevertheless.

 

[Bikemobile]

We do combat reload drills during shooting qualifications, always shoot to empty and reload this way. Hundreds of reloads in this manner without an issue on my FS.40.

 

[Rastoff]

My bet is when the mag is inserted firmly, the cartridge hits the underside of the slide and slightly raises the slide.

When the slide is locked back the cartridge doesn't touch the slide. Therefore, it cannot lift the slide to cause what you're thinking.

 

[Jyezahn]

My bet is when the mag is inserted firmly, the cartridge hits the underside of the slide and slightly raises the slide.

It's the inertia from the hand forcing the frame (and consequently the slide) up, while the slide lock remains stationary. You can also accomplish this without a magazine, and just using your hand to simulate slapping a magazine into the well. Releases every time.

 

[BIGMAC116]

M&P is designed to do this. You'll notice it only happens when holding the pistol at a 45 degree angle (as in a combat reload situation).

 

[Rastoff]

M&P is designed to do this. You'll notice it only happens when holding the pistol at a 45 degree angle (as in a combat reload situation).

???

45 degree angle which way? Side to side? Front to back? Or some compound of the two?

Mine seems to do it all the time no matter what angle I hold the gun at.

 

[Jyezahn]

M&P is designed to do this. You'll notice it only happens when holding the pistol at a 45 degree angle (as in a combat reload situation).

That's not true. There is no mechanism to engage or disengage at a 45 degree angle, and it wasn't designed TO do this. It's design ALLOWS it to do this, which is different. That's why there is a warning in the manual. It happens dependent upon how much force you put into it at. Angle has nothing to do with it.

 

[Ditchdigger]

Though I cannot find the link to prove this statement, you can take it for what it's worth.
I came across a q&a awhile back with Julie Goloski. As I recall the question was someone having a difficult time with the slide stop. She went on to answer by saying one of the solutions is to give a bit of a tap when loading a new mag, this will let the slide close on its own. She said that it was in the design of the m&p. I'll continue to search for that link.

As for my .40 FS, it does the same. I don't recall anything about the 45 degree position though.

 

[Titegroups]

There was a thread strarted bu someone complaing the "auto-release" wasnt working.

 

[SSGT Pride]

Yes,normal and not a problem. Myself,I like it.

Mine does same thing...Love it!