Just purchased brand new M&P Shield 9mm. Had one previously, but made mistake of selling it... (another story, but my wife is happy).
Got home and immediately field stripped (no problem), inspected, cleaned thoroughly with Ballistol, and then "tried" to reassemble.
Inserted guide rod/spring fine and ensured it was all the way down and even. Placed the slide on the frame, but could not get the slide back far enough for the slide lock to engage. Removed the slide and rechecked the guide rod/spring for proper fit, alignment, etc. Still could not get the slide back far enough to manually engage the slide lock.
Was looking at gun trying to figure out what could be wrong and just flicked the safety lever on then off again for grins. (Safety was off during field stripping.) I then slid the slide back and it went back far enough and I could engage the slide lock.
Anyone else have that problem? What could be preventing the slide from going back all the way? The only thing I can think of is the spring on the guide rod hanging up and not fully compressing for some reason and the cycling of the safety lever on/off was just a coincidence???
Thank you in advance.

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Si vis pacem, para bellum

The recoil assembly must be precisely positioned for smooth reassembly. There are many threads on this subject.
With use and experience, this usually ceases to be a problem.

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Science plus Art

What position was your take down lever in? I've had a couple of weird occurrences with it while re assembling... that and my guide rod/spring.

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ChanceFavorsThe
Prepared Mind

This seems to be a common first post for new Shield owners. It seems the spring is so stiff you really have to yank hard on that slide to get it back far enough to flip the slide stop up. Use the mag to lock it back if you can't do it by hand. After getting some rounds through it and dry racking it awhile it will loosen up. Had mine for three weeks and it's better now.


Dgunnut

Mine was extremely difficult to reassemble at first too. After you have pushed the slide to the rear enough to hit the "wall" you need to go another 1/8th inch. It really was that difficult, yet that simple. After a few hundred rounds, it will get easier. Either that or your muscles will develop enough to make it seem easier.

Chances are it's two things easily fixed-

The one is, yes, the recoil spring assembly (aka Guide Rod) on the Shield is ridiculously stiff (necessarily so in order to facilitate proper operation of a striker-fired pistol of this size and reliability etc.) ... when my Shield was brand new, I had to kind of triple-tap it when racking it back to get it locked back, like, rack-Rack-RACK IT (And on the third time I'd have built up a bit of momentum and I could then simultaneously push up the slide stop button to lock the slide back).

The recoil spring assembly is in my humblest opinion the weak link of the Shield; however, I love my Shield and believe it to be an awesome CCW firearm.


Secondly, as mentioned, the guide rod DOES need to be PERFECTLY placed to re-assemble properly... I didn't know this, and wound up having some serious problems and couldn't get it reassembled nor locking back right... I wound up ruining the guide rod , bending and ruining the circular tip on the end (the metal circular end just got destroyed). They had to send me another one, which I am much more careful and particular when re-assembling it.


Once you get the hang of it, you'll be golden, you just need to get the nuance of it down, it's not like a Glock with a pretty much foolproof and idiotproof guide rod assembly that just does it's thing so easily.

I have the same issue with my .40 Shield. No matter what I try there are times when the slide will just not lock back. I'm a big guy and tried with all my might and no dice. I think either the guiderod spring assy gets hung up on something or the smaller rod gets stuck. I ended up calling S-W and explained my situation. At first they said everything in this post about stiff springs, etc but after I explained the slide would simply stop and could not be locked back they offered to send me a new spring assy. It was on back order so I'm still waiting. Hope its better quality than the one I got in my shield!

Wonder if a different recoil spring assembly would work like Wolf.
My first Shield I always put the take down lever down and then released the slide. This time I just TRIPLE CHECK that the gun is unloaded and magazine removed and pull the trigger to release the slide. Putting the slide back on the take down lever was still it its UP position. Maybe it is the guide rod hanging up on the spring. Again, probably more rounds will loosen things up. Putting the magazine in and then reattaching the slide seems to work.

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Si vis pacem, para bellum

I had the exact same issue when mine was new. You really have to yank the slide back. Don't baby it. It gets ALOT easier over time after you put a few rounds through it.

I've had my shield 9mm for a month now & have put 350 rounds through it & it still gets hung up sometimes during reassembly. I've haven't had any failures of any type so far. I found that if I can't get the slide lock back on the 1st try when reassembling, I simply stop pulling & bring the slide back forward, then give it an even firmer tug to the rear while keeping the frame & slide as steady as possible. This has worked for me & doesn't require me to take the slide back off & check the recoil spring. I just make sure the guide rod/spring assembly looks nice & straight & level.

I have a pre-M2.0 9mm Shield, and just got 2 each of the 9mm Shield M2.0. One of them has this problem, while the other does not. Here's what I discovered. When I disassemble, the take down loever is pretty much in the "12 O'Clock" position, or perpendicular to the action of the slide. My Slide Lock will NOT engage the slide lock notch on reassembly UNLESS I move the take down lever to about the 11 O'Clock position. Then the slide lock engages perfectly, and without superhuman effort pulling the slide rearward. Can anyone who has this issue try this solution, and tell me if it's common? I'm a big guy, and I assure you I am moving the slide all the way rearward. If the take down lever is not at about 11 O'Clock, it will not engage the slide lock.

Because I bought two units, I swapped the slides and discovered the problem followed the slide. FWIW.

If you look at the recoil spring shaft you will notice that the part that fits onto the barrel is flat on opposing sides. the curved part of this needs to fit prissily into where is rests on the barrel.
Please see photo.

Attached Images

Recoil shaft.jpg (38.3 KB, 13 views)