M&P's slide stop disengaging

[QuickStrike]

Shot 250 rounds through my M&P 45 today with no feeding/ejection problems.

But after slide lock, when I slam the magazine upwards the slide would automatically close. Once closing on an empty chamber.

I'm not slamming the mags up too hard, but not too gently either.

What would fix this? Should I file/alter the angle on the slide stop surface where it contacts the slide? :confused:


Maybe I should send it off to correct this problem along with trigger work + different sights. :cool:

[Robb Jensen]

You might need a new slide catch or you might just need the edge of it cleaned up and made a little more square.

[Kilroy]

When I see that it's usually a shooter who partially inserts a magazine......here's the windup....now the pitch.....and they slam their hand against the bottom of the magazine. An example of using two hand motions to insert a magazine where one will do. A cupped hand slamming that magazine into place may hit the bottom of the frame first, causing it to jar the slide loose before the magazine has a chance to seat. Another possible consideration is that the slamming motion moves the magazine, but the weight of the cartidges causes a momentary hesitation in feeding. That is the rounds, due to their weight, don't catch up to the feed lips by the time the slide starts forward.

Some folks view this "automatic release" as a feature. I don't think it is.

[Trim2L]

When I see that it's usually a shooter who partially inserts a magazine......here's the windup....now the pitch.....and they slam their hand against the bottom of the magazine. An example of using two hand motions to insert a magazine where one will do. A cupped hand slamming that magazine into place may hit the bottom of the frame first, causing it to jar the slide loose before the magazine has a chance to seat. Another possible consideration is that the slamming motion moves the magazine, but the weight of the cartidges causes a momentary hesitation in feeding. That is the rounds, due to their weight, don't catch up to the feed lips by the time the slide starts forward.

Some folks view this "automatic release" as a feature. I don't think it is.

I can slam the magazines into my M&P as hard or soft as I want and it doesn't release the slide. Call S&W.

[NCPatrolAR]

All of my M&Ps drop the slide when mags are inserted with any degree of force. I have yet to have them not chamber a round though. I dont view it as a problem. If you do view it as an issue though, call Smith. They have countless people asking about this, so it wont be a foreign "problem" to them.

[Erick Gelhaus]

Concur with NCPatrol. I've seen several 1911s and Glocks do this. It happens.

If it is failing to chamber a round, you can either get a S&W armorer on it or manualy run the slide every time it closes on its own while loading.

[bullitt5172]

All of my M&Ps drop the slide when mags are inserted with any degree of force. I have yet to have them not chamber a round though. I dont view it as a problem. If you do view it as an issue though, call Smith. They have countless people asking about this, so it wont be a foreign "problem" to them.

My new M&P 45 will do the same thing. My Glocks will do it once in a while also, doesn't bother me.

[98z28]

Maybe I should send it off to correct this problem along with trigger work + different sights. :cool:

I like the way you think. I had an M&P 45 that did the exact same thing. The slide releasing when I insert a magazine does not bother me. That's one less motion I have to make. It bothered me when it released without chambering a round a couple of times. :eek: It would release when the mag was inserted with very little force.

I sent it back to Smith, they put a much stiffer slide catch in it and the problem was gone. I didn't think they were still using the old slide catches though. I bet gotm4 is correct and your catch is just not as square as it needs to be. Any decent gunsmith should be able to fix the problem, but Smith will fix it for free. Something else to think about: I had to send mine back three times for various problems and it always came back with extra goodies (magazines and night sights).

[Stephen_H]

If the slide is dropping on an empty chamber, then you are more than likely inadvertently brushing the slide stop while manipulating the pistol for reloading. If it is dropping after the mag is inserted and a round is chambered then all you did was save yourself a second or two. I wouldn't worry about it, but YMMV.

It has happened once or twice with my M&P45 and fairly routinely with my Glock 34.

Stephen

[Joe R.]

This is a relatively common occurrence with polymer framed pistols. It's not just a result of the amount of force used in seating the magazine but also the direction that force is applied.

If you insert the magazine and apply the force straight into the grip chances of this happening are reduced. If you apply some forward motion to the insertion of the magazine (moving your hand towards the front of the gun) it can compress the recoil spring just enough to jar the slide and release the slide stop.

Normally the slide will pick up the top round in the magazine when this happens. However given that there was enough force to jar the slide stop loose, it is also possible that there was enough force to compress the magazine spring, lowering the top round a bit and thus allowing the slide to close w/o picking up the top round. I have seen both happen many times and can intentionally chamber a round this way most of the time on a Glock (and as I just discovered on a 9mm M&P). I DO NOT recommend this as a technique to chamber a round...it's just something to be aware of.

Of course as Stephen said it could also be as simple as your inadvertently hitting the slide stop when your inserting the new magazine

[Erick Gelhaus]

Of course as Stephen said it could also be as simple as your inadvertently hitting the slide stop when your inserting the new magazine

Joe & Stephen -
Thanks for that reminder. I don't have that slide stop problem on my side of the pistol.

[Oscar 319]

I must admit that I use this "feature" on all my Glocks (17, 22 and 27) when performing quick reloads. My M&P 45 does this with minimal force, though I can control it. Right or wrong, it works for me. My 1911 seems to have not come with this "feature". :D

[nickdrak]

Every M&P I have ever handled has dropped the slide forward upon seating a magazine during a typical reload for me. This includes the two that I own, and four others that co-workers own.

Rarely when condiucting a reload the slide will not drop, but more often than not it will for me.

On page 17 of the M&P owners manual it states:

"WARNING: DO NOT USE EXCESSIVE UPWARD
FORCE WHEN INSERTING A LOADED MAGAZINE
INTO THE PISTOL. EXCESSIVE UPWARD FORCE
COULD CAUSE THE SLIDE TO MOVE FORWARD,
CHAMBERING A ROUND AND MAKING THE PISTOL
READY TO FIRE."

[QuickStrike]

If the slide is dropping on an empty chamber, then you are more than likely inadvertently brushing the slide stop while manipulating the pistol for reloading. If it is dropping after the mag is inserted and a round is chambered then all you did was save yourself a second or two. I wouldn't worry about it, but YMMV.

It has happened once or twice with my M&P45 and fairly routinely with my Glock 34.

Stephen

This might be the case. I'm going to buy some dummy rounds to test it out. If the slide consistantly chambers a round every time while going forward then everything is fine.

Can anyone recommend a smith to work on the M&P and glock 19?? I'm looking to change out the sights on both and changing out the mag release on the glock too.

[buzz_knox]

Can anyone recommend a smith to work on the M&P and glock 19?? I'm looking to change out the sights on both and changing out the mag release on the glock too.

Most any smith can peform these tasks. In fact, if you are handy (which I'm not), you can do them yourself.

If you want something else done (stippling, trigger work, etc) then David Bowie and Dan Burwell have both been highly recommended.

[ToddG]

I must admit that I use this "feature" on all my Glocks (17, 22 and 27) when performing quick reloads. My M&P 45 does this with minimal force, though I can control it. Right or wrong, it works for me. My 1911 seems to have not come with this "feature". :D

YMMV, but I've seen many students and competitors rely on this "feature" only to have it fail at the worst possible time. While there are exceptions, usually an auto-forward is a sign you may be using much more force to insert the magazine than necessary. Apart from the possibility you could be accelerating wear on the gun, as a general rule more muscle exertion means less speed.

People think "if it doesn't go forward I'll just hit the slide release or rack the slide," but what really happens is that they expect the slide to auto-forward so they begin pressing the gun forward as soon as the mag seats. THEN they realize it didn't work. THEN they bring the gun back and look at it to figure out what's not working. THEN they drop the slide. THEN they press the gun back out.