What Is Really Going On With the M&P Shield 40?

[Dino1]

That was a long time ago and glock fixed their problem and now has full support on the .40's and has for awhile. The other factor in the glock problem from ages ago was the constant unloading of guns at the end of a shift by LE and sticking that round back into the top position of the mag and it was causing bullet set back in the 180grn bullets increasing the pressure. Both contributing factors were discovered and taken care of long ago. Glock even sent replacement barrels out to people as well as replaced guns.

I so want to comment... but need to refrain. You can not be serious about the Glock comment. You need to get educated about the early .40 failures. And with just standard ball ammo.
Just remember the Glock smiley face rounds you couldn't even reload safely.

 

[Rastoff]

I'm sure that this Shield issue is being overblown due to internet accessibility. Here we've heard of 5 Shields having this issue. When you compare this with the huge number of guns sold, I believe these to be isolated cases. Regardless of the cause, it doesn't seem to be an epidemic.

Also, remember that this is not isolated to the Shield. We have seen at least one .45 with the same results. It too was likely caused by an overpressure round.

I'll leave the fact of the unsupported chamber for another discussion.

 

[modraker]

Plus, I just did an "out of battery" test on both my Shields.
Unloaded, I cocked the gun. Then I pulled the slide back slightly, about 1/8'' and pulled the trigger. Nothing happened. Dead trigger. The striker did not move forward.
Case closed?

Try pushing the slide back about 1/16" with your left thumb then pull the trigger. The trigger wasn't dead but it became a contest between my left thumb and my trigger finger. When I relaxed my thumb a bit, the slide moved forward into battery and then the trigger went.

Now, I guess this really isn't an out of battery occurrence since the slide had moved completely forward before the gun would have fired.

 

[catcus-jack]

If its an ammo problem then why aren't other .40 caliber pistols blowing up all over the place.Sigs,Glocks even fullsize M&Ps are not having the same problem.There is definitely a problem with the Shield.

 

[Comrad]

I don't understand the love affair with the 40. Isn't it just a fat 9? I read the ballistics and with shot placement it doesn't much matter if it's a 9 or a 40. I also read that bullet setback can really increase pressure in an already hot load. So my question is, how accurate is bullet crimp in a mass production facility. Could some be set a little too deep setting up a perfect storm? Be gentle on me, just one old guy's opinion.

 

[TheMystro]

You know guys, given the nature of the industry, we will NEVER ever get full disclosure from either S&W or a ammo manufacture on this. If we are lucky, we will get a watered down public relation spin job that has been gone over 50 times from the legal dept and public relations firm.

 

[Rastoff]

For the record I don't think any of the "kabooms" we've seen here were out of battery conditions. From what I've seen, they are all due to over pressure combined with the partially unsupported chamber.
None of the failures have ruptured the chamber.
Only one ruptured the barrel.
None have resulted in serious injury. (One was saved by his safety glasses.)

According to S&W, these guns have functioned as intended. When presented with ammo that developed too much pressure, the chamber stayed in tact and the excess pressure was forced down in a direction mostly away from the shooter.

 

[Roger S&W]

I don't understand the love affair with the 40. Isn't it just a fat 9? I read the ballistics and with shot placement it doesn't much matter if it's a 9 or a 40. I also read that bullet setback can really increase pressure in an already hot load. So my question is, how accurate is bullet crimp in a mass production facility. Could some be set a little too deep setting up a perfect storm? Be gentle on me, just one old guy's opinion.

Well, with the .40, you not only get a larger, heavier bullet but you get a larger casing to pack more gunpowder into. The result: A more powerful impact to the target. (dare I use the term "knockdown power") This is desired in God forbid, an assault. The faster the BG goes down, the less chance he has to shoot you.
For example: Speer Gold Dot 124+P 9mm has 410 ft. lbs energy.
Speer Gold Dot 165 .40S&W has 484 ft. lbs energy.

Will all these factors make a difference when your life is on the line?

 

[Jboutfishn]

It would appear that all we have is speculation at this point. As I have no dog in this fight, I will speculate as to what could have happened.

A sub compact firearm engineered to handled Saami standards with very little margin of error. We load ammunition to max Saami standards. At this point we are still OK. Now a round gets set back from being chambered a few times. Pressure is now above Saami standards. Maybe that ammunition is sitting on the tailgate of your truck. The sun will heat that ammunition even on a cold day. Temperature up can cause pressure to go up. A very warm round, setback several thousands, we have a problem. Gun's fault? Ammunition's fault? Stuff happens.

Just a thought.

 

[Rastoff]

The faster the BG goes down, the less chance he has to shoot you.

This is absolutely true and is indeed the goal of every defensive encounter.

For example: Speer Gold Dot 124+P 9mm has 410 ft. lbs energy.
Speer Gold Dot 165 .40S&W has 484 ft. lbs energy.

This is muzzle energy. As soon as the round leaves the muzzle, this energy starts dropping. Obviously, the further the round travels, the less energy it will have. The larger the bullet, the more effective it is at transferring that energy. Thus, a 12ga slug (72 caliber) is more effective at transferring its energy than a 9mm (.357 caliber. Not to be confused with a .357 Magnum). So, the larger the bullet, the larger the potential for effectiveness. This is why the hollowpoint was invented. As it expands, there is a larger surface area to transfer more energy.

Will all these factors make a difference when your life is on the line?

Of course they will. So, why not a .45ACP? .44Mag or SPL? The answer lies in variety. Some people just like one over the other. There is not one single study that shows any one caliber being more effective than any other. In fact, one study showed that the .22LR was just as likely to have a one-shot-stop as a .45ACP. How's that for an eye opener?

There is nothing wrong with the .40S&W round. It generates the same pressure as a 9mm. That pressure is a little more in a .40 because the casing is larger so, there is more surface area. This means there is more effective pressure on the sides of the case because there are more square inches to push on. Remember, psi means pounds per square inch. More surface area thus, more pressure even though the number is the same. So, 34,000psi in a .40S&W is more pressure than 34,000psi in a 9mm because of the bigger case.

 

[NCW Ray]

Can't say I blame you, especially if someone besides yourself is going to shoot the gun. Until the exact cause of this happening is found and not just speculation, it is better to stay on the safe side.

I have owned nothing but S&W pistols for over 40 years. Needless to say, I am a huge fan and am not putting down the Shield 40mm but I wouldn't fire one on a bet right now. Simply not worth the risk for me.

I'd think even if the 40mm didn't blow up...40mm in that small of a frame you'd still have one hurting hand, wrist, arm, shoulder...etc! And forget a well placed second shot!!!

 

[Watchdog]

I don't understand the love affair with the 40. Isn't it just a fat 9?

I like that.

 

[red dragon]

2500+ through the 9,1200 through the 40. I've had the 9 longer and the ammo is cheaper.

 

[s&wchad]

I cleaned up this thread.

Keep the discussion civil if you want this to stay open. Focus on your opinion, not that of others.

 

[worm5932]

I believe the issues are isolated. I have a shield 40 with id guess 1600 rounds and no issues. as to the recoil spring causing the issue, when my gun was new it was difficult to manually operate. once I got some rounds down the pipe it broke in very nice, it is still very tight but is very crisp in its cycles. unless the spring fails it will close the slide, I cant get mine to stay out of battery every way ive tried..

 

[scattershot]

In reviewing the reported kaboom from a few days ago here,I find it interesting that Underwood Ammo lists the 135 grain .40 ammunition as +P, and then claims that it meets SAAMI specs. Since there is no SAAMI spec for 40 S&W, how can this be?

Jus' sayin'.

 

[RussC]

As much as the next guy, I would like a definitive answer from S&W as to what's going on. However, that is not going to happen anytime soon it seems.

To post things like the OP did, like blind email comments without offering any source of credibility or documented knowledge of the situation, is in my humble opinion doing a disservice to this forum and to S&W.

The fact that these kabooms happened is bad enough...we don't need to yell Fire! in a crowded theater. An answer will come, and hopefully before anyone is seriously injured. To those that own the .40S&W, you have two options: wait for an answer or continue firing away. Personally, if I owned one, I know what I would do. Each of you that own these need to draw your own conclusions and proceed accordinglg.

Oiltrader

I don't think S&W will ever provide the public an answer for the few reports of Shield 40 blowups. Addressing the issue publicly would invite lawsuites especially if they discover a design flaw.

What if you were one of the Shield 40 owners who where told so sorry not the gun that caused the blowup? S&W will only admit fault if they were found negligent in court.

What I believe will happen is the company will make unannounced design changes. It happens all the time in the world of manufacturing.

Russ

 

[TTSH]

What I believe will happen is the company will make unannounced design changes. It happens all the time in the world of manufacturing.

That's a good bet. It has happened before with respect to other issues and will happen again.

 

[Maddmax]

If its an ammo problem then why aren't other .40 caliber pistols blowing up all over the place.Sigs,Glocks even fullsize M&Ps are not having the same problem.There is definitely a problem with the Shield.

Just a thought. "Some" people (as we all well know) think if a little is good,more is better... I'm wondering how many people have a FS 40 (or a different brand 40) and are shooting "hotter" ammo for the FS,think "If it works in the FS 40 it will/should work in the 40 Shield too ???"

The people I know with 40 Shields aren't having any problems and ARE NOT shooting heavy grain bullets OR "hotter" rounds like they do in their FS 40's of any brand. Part of that reasoning is they are just waisting powder pushing a heavier bullet out a shorter barrel.

 

[feelinlucky]

The "FS 40" (full size M&P 40? ATI FS 40?) is rated for the same ammunition as the .40 Shield... as is any firearm rated for .40 Smith and Wesson. As long as the ammunition conforms to the SAAMI standards for .40 Smith and Wesson, it can be considered safe to use in any firearm designed for .40 Smith and Wesson.

Light grain bullets will likely have more muzzle velocity than heavy grain bullets, but either can conform to the peak pressure limits spelled out by the SAAMI standards. If "hot" ammo exceeds this pressure limit, it is out of spec, plain and simple, and could potentially blow up any firearm.