Slide Won't Lock Back

[awhein]

So I was at the shooting range today and when I fired my last round the slide wasn't staying locked back. The magazine was empty so I put in a different magazine and it still wouldn't lock back. So I took it out and placed it back in slowly and when I pulled the slide back this time it locked in place! So I'm pretty sure that it's not any of my mags after testing several and having the issues continue happen and then suddenly it went away. Any idea what would cause this issue if it's not the magazines?

[Tonimus]

Old magazine springs, too powerful recoil spring, or light loads can all cause this. What poundage recoil spring do you have? What ammo are you using? How old are the mags?

[awhein]

Originally Posted by Tonimus

Old magazine springs, too powerful recoil spring, or light loads can all cause this. What poundage recoil spring do you have? What ammo are you using? How old are the mags?

The mags are only 4-6 months old, as for the recoil spring I'm not sure but it's the stock spring that came in the S&W 1911 E series which is only 6 months old. As for the ammo I was shooting winchester white box from walmart. It was happening even when I would just cycle it by hand.

[Tonimus]

Did you put a shock buffer in it?

[davidalyn]

When was the last time you cleaned your magazines?

[Bbrown]

When you cycled by hand, you could get full travel of the slide, correct? Any binding felt?

Possibly the slide stop backing out slightly? Your grip on the gun could be pushing against the slide stop from the right side of the gun, especially if shooting left handed with a two-hand grip, your thumb could rest against it. Or the slide stop binding somehow or even damaged slightly? Doesn't sound like a mag issue to me if it suddenly appeared with different, relatively new magazines.

[awhein]

Originally Posted by Tonimus

Did you put a shock buffer in it?

Nope.

[awhein]

Originally Posted by Bbrown

When you cycled by hand, you could get full travel of the slide, correct? Any binding felt?

Possibly the slide stop backing out slightly? Your grip on the gun could be pushing against the slide stop from the right side of the gun, especially if shooting left handed with a two-hand grip, your thumb could rest against it. Or the slide stop binding somehow or even damaged slightly? Doesn't sound like a mag issue to me if it suddenly appeared with different, relatively new magazines.

I couldn't feel any binding or anything else weird. The mags are super clean and it just seemed like the slide wouldn't catch. I'm right handed but to be honest I'm unsure if I was resting on the slide release. I've never done that before but it's been awhile since I've been shooting my M&P9c lately.

[awhein]

Ok, so I think I figured it out. I spent 30 minutes tonight just loading, ejecting, and reloading empty mags until I could figure out how to duplicate the problem on purpose. What I discovered is if i pushed the followers toward the back of the magazine and then inserted them the slide would not lock back! It also would not eject freely when I released the mags as if the follow was getting hung on on something. It's much worse with the 10 round mags because the follower seems to be a bit larger and slides around more easily but I was also able to accomplish this with my 8 round mags as well. They are all chip mccormick mags and have been very happy with them but now I'm not so sure.

I'm wondering if I should put stiffer springs in them or something. Any ideas?

[Tonimus]

I wonder if your slide stop is out of spec. I cannot recreate the issue you're having with any of my 4-10 rounders or 8-8 rounders.

[Bbrown]

Originally Posted by awhein

I'm wondering if I should put stiffer springs in them or something. Any ideas?

I had to go to Tripp Research Upgrade Kits for all of my mags, made my Baer run flawlessly. You will give up one round capacity due to the extra room taken up by the beefier spring. They make the kits for 8 and 10 round mags, called Super 7 and Super 9. Includes a new follower that engages the slide stop much better on my gun. Might be worth a try.

[devildog8774]

new slide stop for you, sounds like.

[awhein]

Originally Posted by devildog8774

new slide stop for you, sounds like.

If that's the case I wonder if I should send it back to S&W. They have been great about taking care of me so far. With that said, I've never shipped a gun before so I'll need to read up on the right way to do that. I think there's a sticky somewhere on this forum with the proper way to do that do I'll track it down. Thanks for all the help everyone.

[awhein]

Originally Posted by Tonimus

I wonder if your slide stop is out of spec. I cannot recreate the issue you're having with any of my 4-10 rounders or 8-8 rounders.

I'm thinking I could just order a new slide stop instead of sending in the gun and if that doesn't work then send it in. I'm pretty sure S&W would probably send me a replacement but if I were to purchase one does anyone have a suggestion? I'm pretty sure the stock part is MIM so maybe that could be part of it?

[ncdobbins]

I had the same problem with one of my 1911's from another manufacture and had to file a little off of the top of the slide stop lug that is on the inside of the slide. If you look at the slide stop where it fits into the notch on the outside of the slide with an empty mag inserted and the slide in the locked back position, see if it is engaged high enough to hold the slide back. If not, look at the inside part of the slide stop looking down into the chamber to see if the top of the slide stop is up against the frame. After using a jewelers file to remove some material from the top of the inside lug crown little by little, I got the slide stop to fit up into the notch of the slide fully. My gun has worked perfect since I did this. Hope this helps.

[HungrySeagull]

Check the "Ears" to the top and rear of your mags. Are there cracks or out of spec in width developing? The gun actually needs the "Ears" to lock back.

I had a mag the other day finally wear out and the gun did not lock back. I simply scrapped it and put another one to use. I keep a set for training because it is very hard on the mags to fall, bounce or otherwise get thrown around on that concrete floor.

[awhein]

Originally Posted by ncdobbins

I had the same problem with one of my 1911's from another manufacture and had to file a little off of the top of the slide stop lug that is on the inside of the slide. If you look at the slide stop where it fits into the notch on the outside of the slide with an empty mag inserted and the slide in the locked back position, see if it is engaged high enough to hold the slide back. If not, look at the inside part of the slide stop looking down into the chamber to see if the top of the slide stop is up against the frame. After using a jewelers file to remove some material from the top of the inside lug crown little by little, I got the slide stop to fit up into the notch of the slide fully. My gun has worked perfect since I did this. Hope this helps.

Thanks for the suggestion. I'm gonna look at this tonight and see if I can figure anything out. I've pretty much ruled out the mags as they are all like new and I can recreate the issue with any mag I have.

Also, I did order an Ed Brown slide stop which I should be getting in a week. I'm pretty sure S&W would have sent me a free replacement but I wanted to try a part that wasn't MIM.

[devildog8774]

Just be advised that all parts are usually not drop in, I may require some slight fitting for the slide stop, unless you get another one from SW.

[ncdobbins]

Just look at how far the slide stop is going up into the notch in the slide with an empty mag installed and the slide pulled back to locked position, as happens when the gun fires the last round, without manually pushing the slide stop up. Mine didn't have the problem until I had run more than 50 rounds through it. All of the mags I had did the same thing too. The slide stop needs to fit all the way up in the slide's notch to hold it back and not prematurely wear both the slide stop and the notch in the slide. Please let me know what you find out.

[awhein]

I went to a local gun smith today and explained the issue I was having. He confirmed that the issue is the slide stop and that the small face on the inside of the slide is just a bit to short and not hitting the follower to lock the slide back. He also noticed that the spot where they inject it into the mold was causing uneven ware. I told him that I ordered an Ed Brown slide stop and he thinks that will probably solve my issues but if I needed help getting it fit or that doesn't do it to let him know and he can fix it for me. So once I get it I'll post what happens!

[devildog8774]

It will need fitting, everything does, but hope it goes easy for you.

[awhein]

Originally Posted by devildog8774

Just be advised that all parts are usually not drop in, I may require some slight fitting for the slide stop, unless you get another one from SW.

Thanks for mentioning this to me. I thought I would mention that undecided to call S&W to see if they could send me a replacement part but they are currently back ordered at the moment. But that's I'm cause I wanted to put a non MIM part in.

As far as fitting goes I'm guessing I just may need to reduce the size if the pin a hair. I assume using sandpaper to slowly work it down is the best way to go?

[jblackfish]

Originally Posted by awhein

.............As far as fitting goes I'm guessing I just may need to reduce the size if the pin a hair. I assume using sandpaper to slowly work it down is the best way to go?

Probably right on the fitting. For sandpaper use a fine grit and go slow - a little metal removal goes a long way. I'd recommend something between 700 and 900 grit - the smaller the better IMO. It may not be as common as the larger grits but it's worth finding. I have some that's 1500 grit - it's little more than a polisher depending on the metal but it comes in handy to have.

[richpetrone]

I purchased a small MIG welder several years ago at a garage sale for $200. This set had all the accessories and an argon bottle. It has been the best gunsmithing tool I have ever purchased.

I didn't know how to weld, but watched some videos on you tube, and read a lot. I started welding simple flat steel joints, and other odd scraps of steel, and got pretty good results. Estimating how much heat is needed for the work is the trickiest part, but fairly simple. The Lincoln welder I bought has some pretty good codes to adjust the heat listed on the welder itself.

Rather than constantly buying new parts, I now can just about weld anything to fit. I have welded up at least four or five slide stops for better reliability. I have welded mag catch ledges to allow mags to sit higher in the frame. I have welded and fit numerous thumb safeties, since any time you change the sear and hammer, you often need to tweak the thumb safety. I have welded up barrel lower lugs and refit, extended barrel hoods to refit, and have even welded up the rails on a frame to tighten the slide.

The ability to "add metal" when doing gunsmithing is a real plus....and a great cost saver. I would recommend anyone that is a serious DIY gunsmith, to take a look at a small welder and go for it.....especially if the price is right at a garage sale!

[awhein]

I finally got my Ed Brown slide stop and put it in (no fitting necessary) and you could really tell the part felt much better. So I ran though my earlier tests to see if I could still make the same issue happen and it improved but did not disappear. I couldn't make it happen with my Kimber mag but I could with my Chip McCormicks. I noticed the Kimber mag follower didn't really have any play forward or backward so I couldn't cause the problem on purpose where the McCormicks have lots of play. If the follower in the McCormicks is pushed all the way back it doesn't seem to contact the slide lock and if I try to take the mags out it hangs up inside the gun. In real world practice this doesn't happen every time but it's disappointing to think I won't know when I can count on it.