S&W Shield 9mm slide lock issue

[Venom.357]

I had this same problem happen to me once, on my second trip to the range with my 9mm M&P shield, the slide did not lock back on the last round. I was using 115 gr fiocchi rounds. I have run around 500 rounds through this gun, with the majority being fiocchi rounds and it has not repeated since. Unsure as to what exactly happened, maybe i should look at the spring? if this cocurs again i will assum its a mechanical issue.

[n2stackin]

My Shield does the same thing. I open it up and turn the RSA 180 degrees and it corrects it every time. May have something to do with spring orientation. Not sure.

[8mmFMJ]

When you say the last coil must face up...are you saying last coil must face the top of the slide? Or last coil face up when installing (thus last coil face down in relation to the slide)

Thanks.

Last coil must face the barrel

[Malaprop14]

I'm a fan of breaking in a gun with high quality, heavier than normal ammo. For example, Federal American Eagle 147gr for 9mm, or any similar good ammo.

It may not be, or should not be necessary, but IMHO it does eliminate several possible issues that can be caused by a new gun and typical weak ammo.

Someone mentioned maybe your thumb is riding the slide which is also a good possibility.

Since it didn't happen every time, likely a combination of low end ammo and riding the slide a little.

But if you're guide rod assy looks a little bent, certainly contact them for a replacement, but doubt that's causing your problem.

Mine was like that before I even fired a round through it. It manually cycled fine, so I took it to the range and put ~75rds through it. Stripped it again and noticed it looked slightly more bent, or at least more out of place, than before; so I contacted S&W.

Are you able to lock it back manually? Is it difficult to do so?

Mine has not failed to lock back on its own so far, but sometimes IS difficult to lock back manually. That suggests to me that the spring is not seating properly on the guide rod. My FS has thousands of rounds on it and does not look anything like that. It should be flat on both ends, not bent, and the orientation of the spring should not be something that I have to think about on a modern firearm.

[8mmFMJ]

Just got off the phone with S&W (their reps are currently on 15 minute waits due to vacation). So sit n wait, and while you do, get an email ready to send the rep pictures of your issue. If they get it fast enough they can just mail you out a new spring/piston combo. If you don't press the issue they may want you to mail it back.

I was told that if you do not center the spring it will rub, it does not have to be oriented in any specific direction (I was told) but it does have to be perfectly centered onto the barrel notch.

I will be facing the last coil up with the new one anyways as this seems to have solve the issue with the old spring.

Good luck guys!... Back to work

[caligundude]

Thank you all for your help. I will be trying to call to get the spring replaced but i will also try and go back to the range with different ammo and watching my hand placement.

[tbc]

Switch hand and shoot the last round multiple times. If it locked back every time, then it was your thumb that riding on the slide release.

[thegamettt]

also if you don't align that spring properly, it can be difficult to lock the slide back after reassembly. I have this problem almost every single time I reassemble. now I don't even lock the slide back, I just hold it back far enough to turn the takedown lever.

[shakyshoot]

My bet is that it's related to the very tight recoil springs on new Shields. Mine did this a few times on the first couple of range trips. Since then--never. I don't see where you ever said what kind of ammo you were using. My lock-back problems occurred with UMC and Federal Champion. Try some zippier ammo like Fed American Eagle, Winchester white Box, Speer Lawman, or Herters from Cabela's. I'd also do this: Rack the slide manually 50 times a day for 5 days, and leave it locked open 24 hours a day for those 5 days. The Shield springs are very tight out of the box, and 250 cycles is about all it takes to make a difference. I'm betting this will solve your problem.

[jws339]

Mine won't lock back at all just got it no rounds threw it yet need to strip it down but this is pissing me off : (

[shakyshoot]

Mine won't lock back at all just got it no rounds threw it yet need to strip it down but this is pissing me off : (

Got an empty mag in it? If not you have to push the slide stop up manually.

[Malaprop14]

Got an empty mag in it? If not you have to push the slide stop up manually.

Or you aren't pulling it back far enough. The springs are very tight at first as mentioned above. Not pulling it back enough will not allow the stop to catch.

[autoduel]

Same problem here. Was told the spring was installed wrong and the last coil must face up (like a glock?). Must have been from the factory because I didn't strip it before the first 100 rounds. Called them and they are closed for another week.

Mine also didn't last round hold open for 2 mags. The problem has since disappeared with a 180 degree turn of the spring.

Edit: here is a pic

Hard to believe that a linear assembly like a recoil spring needs to be indexed to operate correctly. It seems like the M&P springs are cut down longer springs rather than wound for a specific length with proper terminations that are square. My sig spring sits flat. My 9C looks like your picture, but hasn't had any issues. Why S&W chose to cheap out in this area is beyond me.

[ElDub1950]

Same problem here. Was told the spring was installed wrong and the last coil must face up (like a glock?). Must have been from the factory because I didn't strip it before the first 100 rounds. Called them and they are closed for another week.

Mine also didn't last round hold open for 2 mags. The problem has since disappeared with a 180 degree turn of the spring.

Edit: here is a pic

Last coil must face the barrel

Can you explain this a little more? Regardless of which way the spring is, the 'last coil' on one end or the other is going to face the barrel. Obviously I'm failing to understand. The black on black pic is hard to see anything.

[ifilef]

Gosh, this issue could be caused by so many things, e.g., limp-wristing, not having mag fully inserted, perhaps not having guide rod spring properly oriented, thumb inadvertently engaging slide stop, weak spring that holds the magazine in place (issue resolved with replacement spring in a Kahr CW9 years ago), break-in issues, slide stop break-in issues, under-powered ammo, etc. that we all seem to be speculating.

In any event, I do vaguely recall also that with at least one pistol I have owned in the past manual recommended open end of guide spring should be oriented in the 12 o'clock position when it sits in the 'hood' that encloses it, and as you are inserting it (open end faces ceiling). I have followed this 'rule of thumb' with all semi-auto pistols. IDK, may be urban legend, but I do it anyway.