Solution for Auto Forward Slide Action

Greetings everyone. New to the forum but not a noob to forums.

Just got my M&P45 from my wife as an early Christmas present. Love my wife and the gun. I started reading this forum when I began looking for my first .45. It is a great site and I hope I can contribute some good info. Here is my new 45. Planning on installing an Apex Tactical DCAEK and that's it.


In reading this forum and other places, I noticed that some people were having problems with the slide moving forward when inserting a new magazine. Some said it was normal and no problem and some said guns should not auto forward.

Couple of weeks ago I went to the range and rented a Kimber 1911 Custom II, M&P 45 and a Glock21. All were great guns. The Kimber was dead on accurate. The M&P and the Glock were very similar to each other, with obvious reasons. I chose the M&P because it fit better in my hand and shot a lot smoother. Not as smooth and accurate as the Kimber but smooth enough and accurate for a combat gun.

One thing that happened with the M&P that surprised me was the auto forward slide action. I loaded a magazine with bullets and inserted with the same amount of force as I always do with all my other guns. Not very forceful. SLAM! The slide went forward and chambered a round. It did this a few times. I thought that because it was a rental gun, and had several thousand rounds through it, the gun was just loose and worn out.

Fast forward to Black Friday when I got my gun. Came home like a happy little boy. Check the slide action and trigger. All is fine so far. Opened the slide by hand and locked it in place. Loaded a magazine with bullets, inserted the magazine with light to moderate force and SLAM!. Auto forward. Feeling a little bummed. Brand new gun and its doing the auto forward slide action.

I checked and re-checked everything. I came across a couple of things. The gun would auto forward when the magazine had one or more bullets in it. It would not auto forward with an empty magazine no matter how hard I would slam it in.

Another thing I noticed. When I would move the slide back and either have it lock by itself with an empty magazine in it or when I would manual lock it with my thumb, the slide lock would look like this:


The slide lock would barely catch the slide recess. It would be enough to hold the slide open but when you hit it with a loaded/heavy magazine, the bump/momentum transfer would release the slide lock and the slide would go forward.

I started looking at the gun itself. I noticed that the slide lock lever tab inside the gun was angled ever so slightly upwards. Here is a picture of the tab. Picture taken after I did my modification:

The spring tension in the magazine pushes the magazine follow up. When the magazine it empty, the magazine follower pushes up on the tab and therefore the slide lock lever goes up. This in turn locks the slide back when the slide lock catches the slide recess.

My solution was to move the tab down a little bit. I tapped it a few times with a small brass armorer's hammer. Just enough to bend the tab down slightly. This makes the slide lock lever move up more. The slide lock now looks like this when I manually move the slide back or when the gun runs empty after the last shot.


Went to the range yesterday and shot the gun. No auto forward when inserting a new magazine with normal to moderate force. I fired 200 rounds and the gun operated without a hitch. Obviously, I'm planning on using the gun more. If I run across anything new, I'll keep you guys posted.

Hope this helps.

And I really LIKE having mine auto-slide forward on a reload in USPSA/IDPA matches!!

Randy

all 3 of my M&Ps only auto forward when i slam the mags home with some force. i love the feature.

As long as your slide is going forward when inserting a mag it is working perfectly. If mine did not auto forward I would look at sending it in for repair.

Wow! What an excellent gift from your wife. I'll have to get my wife to read this thread, and maybe she'll take a hint...lol

air8 said:

As long as your slide is going forward when inserting a mag it is working perfectly. If mine did not auto forward I would look at sending it in for repair.

Click to expand...

If this was a design feature, then, yes, send it in. But it's not a design feature. It's a factor of how much force you apply when you insert the magazine and if the slide lock catches appropriately. It is not consistent.

I have 15 years in law enforcement. I've been trained to insert the magazine with adequate force, hit the slide lock, and re-engage the threat. In a combat situation, you will not always apply the same force. If I am stressed and slam in a magazine, I don't what the slide to go forward. I want it to stay and manually release the slide like I'm trained. I don't want the slide to auto forward when I least expect it. I don't want it to auto slide and think, "Hey! What was that? Oh Yeah", look down at the gun to check if it's alright, and then engage. That time it takes to realize what going on is valuable and can be a matter of life or death.

This opinion is all based on my training and experience. YMMV

I have noticed something particular on all new M&Ps in that they do not have the STAINLESS stamped on the left hand side of the slide. has anyone else noticed this omission?

They are still stainless steel slides are they not, or is it all the other stuff they are forced to put on the weapons nowadays?

FWIW when I got my two rebate mags they both gave me the same incomplete engagement of slide stop to slide stop notch that the OP shows a picture of. It didn't happen with my two original mags so I tore down the two new mags and found that the springs were about an inch and a half shorter. New springs in the new mags fixed my problem of auto slide release.

I don't treat the "auto forward" defect as a feature. To be safe ya should still manually cycle the slide.

Gaining seconds or points in gun games can leave you with techniques that really just don't work under stress in the real world. If the slide fails to "auto forward" what ya gonna do now? If you'd manually cycled the slide there's be no question and no momentary brain freeze while you try to figure out what to do.

Same thing with using the slide stop as a slide release. The M&P's is tiny and located in an "odd" place compared to several other pistols. Heck the SIG is back where the safety on most pistols is located and my former Walther PPK didn't even have one. Reaching over and manually cycling the slide always works.

And my favorite: depending on magazines to drop free. Standing there shaking the pistol on the range only looks stupid in front of your buddies but has grave consequences at 0200 in a dark parking lot. Your support hand is already on the pistol. Use it to strip the magazine and go to your belt in one motion. If the magazine fell free there is (again) no brain cramp or puzzlement, just complete the motion and get the full magazine in the pistol, reach over, and cycle the slide.

Keep it simple. Keep it reliable.

-- Chuck

This is another thread where some people are puffing out their chest telling us they are better than others because they have extensive training in proper reloading techniques directly from God, or they shoot 200 bazillion rounds a week and can execute a flawless magazine change while rolling in the dirt, under fire, with one hand tied behind their back.

I like when my slide goes forward, so I am an idiot, but I don't mind. It saves me a step. It is easy. It works. If my slide doesn't go forward I see that it is back, and I rack the slide. My procedure is; insert mag, if slide is back, rack it. If it is forward, I just omit the racking part! Pretty dang easy if I may say so! I'm such a poor gun handler that I actually have to look at my gun to insert a mag, so it's really easy for me to see if the slide goes forward when the mag goes in.

If you ever read about my untimely death because I depended on my slide chambering a round during a tactical reload and it didn't work, and for some reason I didn't notice my slide was back, and the perp was on me in the split second it takes to rack the slide to clear the gun, then I won't begrudge you the opportunity to say "nah nah na nah nah, I told him so! " at my gravesite.

Stainless

Houdini1953 said:

I have noticed something particular on all new M&Ps in that they do not have the STAINLESS stamped on the left hand side of the slide. has anyone else noticed this omission?

They are still stainless steel slides are they not, or is it all the other stuff they are forced to put on the weapons nowadays?

Click to expand...

I recently bought a new M&P9 and noticed the same thing. I called S&W and was told they are still all stainless and they just omitted that one stamping process.

I actually prefer the cleaner look without the word.

Slide going forward

I just took my new M&P9 apart and while mine does not release the slide when inserting a new loaded mag the lever does move down about half way out of the notch if I smack it in a little harder. I wont be surprised if it does release the slide once the gun gets worn in more.

None of my other pistols do this and I'd rather this would not either. I also noticed the tab that contacts the mag follower is angled upward slightly. If it were bent down a little more it would put more upward pressure on the slide release lever.

I'm afraid to bend it cause I did that once on a Glock and the tab broke off.