Any fix for slide failing to lock back on last round?

bigwheelzip

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Using Speer Lawman 124gr., I put 150 rounds through the 9mm Shield today, in fifty 3 round sets, using both OEM mags. The slide locked back only twice.

This is a problem since new, 16 months ago, with multiple ammo brands. Any suggestions?
 
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Any feeding problems? Failures to feed or eject?

If it's 16 months old I guess its been cleaned and lubed, but are you using oil or grease on the slide?
 
Four common problems with failure to lock back:

1. Wimp ammo
2. Wimp grip ( I don't mean squeeze the gun, I mean lock your arms all the way back to your shoulder and chest muscles) yooutube seeklander - Bing video
3. Riding slide or slide lock with thumb, which is easy to do on a Shield
4. Improper/ insufficient lube

Rarely, there can be a factory defect
 
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Any feeding problems? Failures to feed or eject?

If it's 16 months old I guess its been cleaned and lubed, but are you using oil or grease on the slide?

Never had a feeding problem with it, and only use 115gr or 124gr American Eagle, Federal Champion, or Speer Lawman for plinking and 147gr HST Standard pressure for SD.

Its cleaned and lubed each time its used (monthly) with Hoppe's 9 solvent and oil and Mil-Comm TW-25b lube for slide grooves and tabs.
 
Speer Lawman is good stuff. I use that and Blazer Brass in both mine and my wife's Shields and there have been no problems at all.

Limp wristing or accidentally getting a finger on the slide lock button could cause it. Have someone watch you shoot the gun focusing on where you're fingers are in relation to the button.
 
Four common problems with failure to lock back:

1. Wimp ammo
2. Wimp grip ( I don't mean squeeze the gun, I mean lock your arms all the way back to your shoulder and chest muscles)
3. Riding slide or slide lock with thumb, which is easy to do on a Shield
4. Improper/ insufficient lube

Rarely, there can be a factory defect
Good ammo, locked Isosceles, and attentive maintenance.
My thumb doesn't ride, but barely touches the underside of the slide lock. On such a small grip, where should you put your thumbs?

Is there a part that I can check, to see if it's in spec. that might be the cause?
 
I have two early Shields. They were finicky about ammuntion until I replaced the recoil spring assemblies. You can't usually get them from S&W. There are third party vendors who make nice ones in stainless steel.
 
I have two early Shields. They were finicky about ammuntion until I replaced the recoil spring assemblies. You can't usually get them from S&W. There are third party vendors who make nice ones in stainless steel.
I have an OEM replacement RSA for the one that failed when the gun was new. Just occurred to me to switch the RSA's with the one in my husbands Shield and see what happens. Thanks.
 
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Check the slide release to ensure it's correctly installed and has the requisite spring tension.
Is that something that needs to be done by a gunsmith? Just by observation, I can't see any difference between mine and my husbands.
 
Is that something that needs to be done by a gunsmith? Just by observation, I can't see any difference between mine and my husbands.
It requires a detail strip and reassembly. There are online instructions if you're comfortable; if not, any S&W armorer can do it.

Might be you can just do a field strip and look to see if the slide stop spring is in place.

Failure to lock back on the last round can have a lot of causes, but a troubled slide stop is the first one I look at; magazines second.
 
Ages ago, I had experienced a similar situation with a 1911. I think that the principal and geometry are similar with the Shield. I will make the dangerous presumption that you and your husband are interchanging magazines between your pistols, and that his functions properly with yours. If that is a safe presumption, it is then time to look at the slide lock itself.

There should be a small projection from the slide lock that passes through the frame and interacts with a small "L" foot on the magazine follower. It is this interaction that engages the slide lock. If the projection is too short, or the magazine follower "L" is deformed, the slide will not lock back.
 
Same thing happens with my husband shooting mine, but no problem at all when both of us shoot his.

Knowing this bit of info I would now think the problem is with the gun itself and not the shooter. I would look closely at the slide lock button, mainly the part that contacts the magazine follower plate, and compare that to the one on the "working" Shield. Could be that tab needs a little tweaking.
 
Not yet, I'm not eager to send another gun back to them unless I have to.

I had the same problem with my shield 9. I thought it was a magazine problem, I even had S&W swap one out (which they did with out issue). It was driving me nuts and I was really starting to question the gun for self defense. I ran through every type of ammo from reloads to brass casing to aluminum casing and just beat my head against the wall because sometime the slide would lock but mostly it wouldn't. I found out it was me the whole time. I shoot with my thumbs forward and my right thumb would contact the slide release lever just barely and it would cause it to stay down. Once I was mindful of this and kept my thumb away from the lever I never had another issue with the slide locking back. Took a bit of practice but issue is 100% resolved and my shield will eat anything and ask for more. Remember that the only thing pushing the slide lock up is the mag spring so it doesn't take much to stop it. Also being a single stack your hand wraps around the grip more. Hope this helps.
 
presumption that you and your husband are interchanging magazines between your pistols, and that his functions properly with yours.
No we have not done that yet, only tried the two that came with mine. Can try that next, along with RSA.
 
Knowing this bit of info I would now think the problem is with the gun itself and not the shooter. I would look closely at the slide lock button, mainly the part that contacts the magazine follower plate, and compare that to the one on the "working" Shield. Could be that tab needs a little tweaking.
Will inspect it, thanks.
 
I had the same problem with my shield 9. I thought it was a magazine problem, I even had S&W swap one out (which they did with out issue). It was driving me nuts and I was really starting to question the gun for self defense. I ran through every type of ammo from reloads to brass casing to aluminum casing and just beat my head against the wall because sometime the slide would lock but mostly it wouldn't. I found out it was me the whole time. I shoot with my thumbs forward and my right thumb would contact the slide release lever just barely and it would cause it to stay down. Once I was mindful of this and kept my thumb away from the lever I never had another issue with the slide locking back. Took a bit of practice but issue is 100% resolved and my shield will eat anything and ask for more. Remember that the only thing pushing the slide lock up is the mag spring so it doesn't take much to stop it. Also being a single stack your hand wraps around the grip more. Hope this helps.
My thumb just barely touches it, but there is so little room for it to be anywhere else. I am going to try one-handed lefty next time to eliminate the possibility.
 
If the size of your Shield and it's ergonomics actually appear to be the problem because of how you HAVE to grip it, may I make a suggestion?

I believe that the Mauser HSC is about the size of your Shield, and I realize that it is a 380. However, the frame and slide are clean, no levers. The slide release is completely internal ... it goes into battery as a clip is inserted into the grip. I carry mine (when I carry it) with Hornady Critical Defense ammo.
 
If the size of your Shield and it's ergonomics actually appear to be the problem because of how you HAVE to grip it, may I make a suggestion?

I believe that the Mauser HSC is about the size of your Shield, and I realize that it is a 380. However, the frame and slide are clean, no levers. The slide release is completely internal ... it goes into battery as a clip is inserted into the grip. I carry mine (when I carry it) with Hornady Critical Defense ammo.
Thanks for suggesting an alternate. Reminds me of the Walther PPK which I always liked. It's sacrilege to say on a forum skewed to the classics, but I'm not comfortable buying used or or out-of-production firearms without warranty, due to my limited gun knowledge.

I do have a Sig P238 in my carry rotation, that I also shot yesterday. It predates my Shield, but has never had a problem, and seems to get better with each outing. So, .380 is covered.

Except for the slide locking back, The Shield has been dependable since installing the replacement RSA. I've been resigned to manually racking on reload, which is not the end of the world, just made a bit more annoying since my husband's Shield is fine, and I bought him that Shield too.
 
Is that something that needs to be done by a gunsmith? Just by observation, I can't see any difference between mine and my husbands.

The slide stop spring is designed to keep the slide stop in the down position, so even if the slide stop spring was missing, an empty mag would lift it into the hold-open position. The spring is there to drop the slide stop it when a loaded mag is installed.
 
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With the pistol empty, slide closed ,no magazine , see if the slide stop lever is held down . It should have spring pressure down, but very light , just enough to keep it down. If that's the case then that isn't the issue. Are the magazines in those guns able to be disassembled ? I don't have one, so don't know , but if they can be taken apart , do so and give all parts and the body itself a good cleaning. Make sure the follower ( the follower is the part inside generally plastic in newer guns, that the bullets sit against )is coming all the way up to where it would contact the slide release lever and push it up.

Here is a video that shows an M&P magazine being taken apart to give you some idea. Not a complicated process, and one that is a good idea from time to time.

[ame]https://www.youtube.com/watch?v=wXDgEh-PTK4[/ame]
 
With the pistol empty, slide closed ,no magazine , see if the slide stop lever is held down . It should have spring pressure down, but very light , just enough to keep it down. If that's the case then that isn't the issue. Are the magazines in those guns able to be disassembled ? I don't have one, so don't know , but if they can be taken apart , do so and give all parts and the body itself a good cleaning. Make sure the follower ( the follower is the part inside generally plastic in newer guns, that the bullets sit against )is coming all the way up to where it would contact the slide release lever and push it up.
Thank you for the detailed troubleshoot procedure. It's as you describe, Slide Stop being held down by light spring pressure. The Follower in an empty Mag is pushing the slide release lever up some distance. I disassemble and wipe the Mags, Follower, Spring, and Base Plate with Hoppe's 9 and then a dry wipe, every time I shoot.

Great lesson, taught me a bunch, and thanks again. Didn't discover anything obvious. Maybe I just need to work on a different grip, like planting my thumb near the Mag release.
 
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