PSA Rusted M&P Shield Safety

[ajamesp51]

Everyone that owns an M&P pistol needs to take a look at this article I just wrote. The scary thing is that it was a 40Sw Shield. And with all of the recent kabooms of 40 Shields, this got me thinking that my customers gun could have been next. In a short time his gun would have been too dangerous to use. But in all outward appearances the gun seemed just fine. Please feel free to share and go inspect your M&P's. I have seen this on a couple of slides when doing installs, but never this bad. I always just cleaned them for the customer, but this has me thinking.

Rusted Smith & Wesson Shield Safety - Tacti-Cool.com

 

[agksimon]

Wow! What an eye opener. I just changed out the sights on my Shield a couple of weeks ago and it was fine. Do you think it was caused from getting wet?

 

[HeavyDuty Ken]

I don't see an obvious safety issue there at all, unless maybe you put it in a drawer for a few decades first. It looks to me like either the sight base rusted a little or there was residue from fitting that rusted. None of my three M&Ps had anything like this, either.

A little surface rust rarely makes anything go kB.

 

[UncaGrunny]

Considering the location of those parts, it seems like it would take a LOT of water to get them wet at all - especially if it was reasonably well-oiled. Like, "dropped in a pond" level wet, as opposed to "caught in the rain" level wet.

 

[shipwreck]

Interesting photo.

 

[radar1972]

Considering the location of those parts, it seems like it would take a LOT of water to get them wet at all - especially if it was reasonably well-oiled. Like, "dropped in a pond" level wet, as opposed to "caught in the rain" level wet.

Agree. And from the photos with the article, I would guess salt water.

 

[Bozz10mm]

Disturbing. I hope this is uncommon.

 

[vipermd]

I looked at the photo and could see no correlation between the rust and kabooms. I then read his article,which also has photos. It demonstrates how extensive the rust can be, while not visible on casual inspection. The article is informative and thought provoking, since I have not been doing a through breakdown after severe water exposure. No rust on the sight base will not cause kaboom, but should make you look farther for other possible problem areas. Thank You for taking the time to write and photo. Be Safe,

 

[ajamesp51]

The customer stated the gun had never been wet, the wetness you see in the pictures is oil.
(I do not see any evidence of salt)
I have actually seen others that have rust in the safety, but I always just wiped it out since it was minimal. And never though twice about it until I say this one.

And the safety was already gritty and it would not have taken long to get stuck enough to be impeded.

I looked at the photo and could see no correlation between the rust and kabooms. I then read his article,which also has photos. It demonstrates how extensive the rust can be, while not visible on casual inspection. The article is informative and thought provoking, since I have not been doing a through breakdown after severe water exposure. No rust on the sight base will not cause kaboom, but should make you look farther for other possible problem areas. Thank You for taking the time to write and photo. Be Safe,

Yes the whole point is to share information and add this knowledge to your tool box.

 

[uechikid]

Thanks for sharing this. So much for stainless steel being rust resistant.

 

[Offshell]

Wonder how the apex parts will hold up in comparison.

 

[red2rider]

I would almost bet that somewhere along the line either before the owner or during that that gun got really wet and not cleaned up. Parts like that just don't rust that quick unless moisture has gotten to it.
It is a good thing you caught it early enough before failure occurred. And a good armorer at that for taking the time to investigate it further and deal with it.
What state was this gun in? Some folks just sweat a lot. I could see that causing an issue. Like you said, once rust starts it just keeps going.

 

[Bozz10mm]

After reading this thread, I went ahead and removed the back plate and inspected the striker for rust. Fortunately, mine is clean as a whistle. I didn't see anything on the striker block either. I didn't remove the rear sight, just used a flashlight, but what I could see was clear of rust.

I've only had the pistol since December last year with only 260 rounds through it. It has never been exposed to water, but I carry it daily. This is probably not going to be a wide spread problem, but it would be a good idea for everyone to at least pull the back plate off and inspect the striker.

 

[t1.8matt]

Would alot of sweat getting on the slide cause this?

 

[emory]

I am going to guess that the owner had night sights installed. The fit of the rear sight is very tight and the installer of the new rear sight removed a bit of material from the bottom face with some abrasive. The S&W slide is surface hardened stainless, but the aftermarket sights were probably machined from heat treated 4130 or similar carbon steel. Water, humidity, or sweat found its way in there and caused the corrosion on the bare metal at the lower face of the rear sight. It would not require immersion: prolonged contact with damp cloth would be enough. Liquids can be drawn into small gaps through capillary action. The free fatty acids in sweat are known to increase the rate of corrosion. Just my wild guess anyway.

Clean and oil, everything will be fine.

 

[ajamesp51]

I am going to guess that the owner had night sights installed. The fit of the rear sight is very tight and the installer of the new rear sight removed a bit of material from the bottom face with some abrasive. The S&W slide is surface hardened stainless, but the aftermarket sights were probably machined from heat treated 4130 or similar carbon steel. Water, humidity, or sweat found its way in there and caused the corrosion on the bare metal at the lower face of the rear sight. It would not require immersion: prolonged contact with damp cloth would be enough. Liquids can be drawn into small gaps through capillary action. The free fatty acids in sweat are known to increase the rate of corrosion. Just my wild guess anyway.

Clean and oil, everything will be fine.

NO that is not what happened. The sights were factory and had never been removed before. Everything was factory. The customer sent me the slide to install a set of after market sights. This was discovered as I was removing the factory rear sight.

 

[Smitty357]

I've taken my Shield down plenty of times. And ive never found a single tiny piece of rust on mine. I've had mine since the day the Shield came out and i carry it 12+ hours a day 5 days a week. Also mine is still 100% stock, aside from the 9mm conversion barrel that i bring to the range on a daily basis. Maybe i'm like MANY others and i got a perfectly good Shield with 0 problems.

 

[rickyfinch]

Looks like 99% surface rust. Maybe the pistol took a salt water bath? Was he the first owner? I agree if this is wide spread it is a issue. However my shield .40 looks like brand new on the inside. I have between 750-800 rounds. I'm curious to know the real story as to why this happened.

 

[emory]

NO that is not what happened. The sights were factory and had never been removed before. Everything was factory. The customer sent me the slide to install a set of after market sights. This was discovered as I was removing the factory rear sight.

Alright, before my last post I had only seen the image in this thread on my smartphone. Now I have sat down at a computer and followed the link as well. Lots more photos there. Certainly there is a lot of gunk in that shield. Certainly the gunk has the color of rust. It is not clear from the photos which parts are corroded and which are simply exposed to the products of corrosion. Corroded parts would have visible pitting after a good cleaning. The striker, striker block, and spring are clearly made from a stainless alloy. They are very unlikely to be a source of corrosion. The bottom of the MIM rear sight appears to be bare metal and looks pitted to me. The outside surfaces of this part should be passivated and they do not appear to be. This is definately an ugly mess, but I would not go so far as to speculate that failure of a safety mechanism was imminent or to label this as a "dangerous condition" or a "disaster waiting to happen."

 

[Dino1]

Maybe non temperature controlled warehouse storage.
That seems very odd. That one got wet, it is very obvious.
Was the bottom of the sight filed down to get it to fit?