While at the range yesterday after many rounds the trigger could not be pulled back. After removing the mag and racking the slide a few times everything seemed to be back to normal. Cut to the chase, I realized the magazine safety was not working. I haven't stripped it yet but I'm not even sure what to look for. Google has not turned up a parts diagram. I've held it next to another one just looking down the breech and don't notice anything different. Anyone have any suggestions.

OK, if the 952 follows the pattern of the other S&W semis, the magazine safety is operated by a spring loaded nylon plunger in the slide that engages the ejector. When the magazine is removed, the plunger depresses the ejector which pulls the disconnector down and disengages the draw bar from the sear.

Start with a thorough cleaning. Then, looking at the bottom of the slide, on the (single) safety side of the slide, you should see a white nylon plunger. Make sure it moves freely. Then, looking at the frame, see if the trigger engages the sear (DON'T LET THE HAMMER FALL). If it does, depress the ejector until it's flush with the frame and make sure the trigger no longer engages the sear. Slops back and forth.

Added edit: if depressing the ejector flush with the frame doesn't disconnect the trigger, it's likely the disconnector has somehow been damaged and requires replacement. If the nylon plunger in the slide doesn't move freely (and depress the ejector when the magazine is removed), the plunger and/or the spring requires replacement.

I think the 952 is a bit different, I don't see the white nylon piece you are describing. I've tinkered with it a bit today and also opened up another 952 to look for any noticeable difference and am not seeing anything. One or two things I'm a bit suspicious of. Also discovered that the grip safety is not functioning so I'm sure the two things are related. I'll tear back into them again soon. Also going to email S&W and see if they have a parts diagram. Thanks.

Well, if it is a 952 no dash, there is no grip safety and the MSH does not move. If it is a 952-1 or dash-2 (or the hyper scarce dash-3) then the grip safety is a Swartz-style firing pin lock and should not affect trigger/sear at all. To put it another way, the 952 grip safety does NOT work like a 1911/945 grip safety. A 1911/945 grip safety will not allow the trigger to be pulled if it isn’t squeezed, the 952 will.

As for your magazine disconnect safety, this is best checked with the slide off.

I have one guess for you: perhaps it is NOT the magazine disconnect safety that is impeding your trigger pull. It may not be well known, but the 952 features an adjustable trigger over travel stop, and like every such one of these, if it is maladjusted, it will absolutely prevent the trigger from being pulled enough to trip the sear.

It can be found in the drawbar and accessed from the top of the frame with the slide off. A picture here would help a lot but I don’t have one at the moment.

A trigger over travel stop that is loose can slowly take itself out of adjustment in the normal course of shooting and if it moves too far, it can prevent shooting until it is properly adjusted.

Try and dig around your pistol a bit and report back, if I need to take some pictures let me know and maybe I can do that tomorrow.

Its a 952-1 and no problem with the trigger over travel. I was at the range when the tigger wouldn't pull back, I cycled the slide a few times and all was okay, probably shot another 50 rounds. Didn't even notice it until later when I was cleaning later on. I've got a couple more so I'll take off all the slides and look for something thats not quite the same. Called S&W but no luck on a parts diagram. I may just live with it because there is a point where I no longer feel comfortable taking it apart.

Not to try and force feed you a dead horse (haha mixed metaphor) but the trigger over travel stop on a 952-1 is really, REALLY not obvious and also not to be confused with the fairly obvious trigger pre-travel adjustment screw.

While it's not a 952, Numrich had/has a skematic of the model 52, which is at least a cousin to the 952.

The parts diagram does show the slide mounted plunger & spring (under the rear sight) to power the magazine safety.

It also shows both an upper and lower trigger stop screw as noted by Sevens above. On the model 52, the upper is the pre-travel adjustment. The lower screw (on the diagram) is shown going in from the rear of the frame. It doesn't show where it is or how one gets to it for adjustment. However, after looking at the innards of a normal S&W I kinda expect that the over travel screw might be in the forward part of the drawbar and in between the upper legs of the trigger.

I believe I have that diagram as I used to own one so I'll check that out. However, I don't understand the interest in that part as the gun only failed that one time and it continues operate just fine except the two safety mechanisms. That said, it still bugs me and I want to figure out what went wrong so I'll be checking everything I can get to.

Well the interest is because I haven’t experienced a S&W failure related to the magazine disconnect but what you describe sure sounds like a migrating over travel screw, which I have experienced a few times in handguns.

Also seems worth adding that I have seen many different versions of a trigger over travel stop adjustment across different handguns, but the one they use on the 952 is the most NOT obvious one I have ever seen, literally ever. I’m willing to bet that many or perhaps most 952 owners may not realize that it exists.

I do have a very good 52 diagram in Jack First's book and appears similar to 952s so it looks like a good place to start. Trial and error or do you have a suggestion to loosen or tighten, upper or lower?

Both the 52 and 952 have a two way adjustable trigger, but only the pre-travel adjustment screw is similar between these two models. On the 52, the trigger over travel stop screw is located in a very traditional spot, directly behind the trigger itself where you would expect it to be located.

On the 952 however, it’s location is unique and as far as I’ve seen, not many other guns are like it.

If either the pre-travel or over travel screw is maladjusted, a failure to fire can be the result.

If the pre-travel is screwed too far than the trigger is not allowed to reset, net result: no bang.

If the over travel screw is screwed too far then the trigger cannot trip the sear, net result: no bang.

Here’s the thing...
If somehow the magazine disconnect safety is malfunctioning or otherwise not defeated, the trigger can still be pulled to the rear, however the drawbar won’t actuate the sear.

But if the trigger over travel stop is maladjusted, the trigger won’t physically be able to travel enough distance rearward to trip the sear.

These very small screws can migrate on their own, over time, in the course of live fire. And it would be expected that if they were moving on their own, intermittent failures could be the result.

Without the pistol in my own hands, I obviously can’t be sure.

I will say this with full confidence: if you cannot figure this out, please don’t try to get S&W involved. They are wholly unqualified to even be in the same room as this pistol. Almost nobody employed there has half a clue about a 952 and this is not hyperbole, this is the sad truth.

If you end up at wits end, I would suggest to send a PM to great forum guy and gunsmith guru BMCM, I have no doubt that he can get to the bottom of this.