S&W M&P40 Ammo alert, and question

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Coronach

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1. I have found a type of ammo that does not seem to work well with the M&P40. As you can see at the bottom of this page, I have not yet had a fail-to-feed with my M&P, at least up until last night.

I have been feeding it Fiocchi 170gr FMJFN (Full Metal Jacket Flat Nose). It digests it just fine. I recently got a few boxes of Fiocchi 170gr FMJTC (Full Metal Jacket Truncated Cone). It was sold as being the functional equivalent of FMJFN. In actuality, it should be called the non-functional equivalent of FMJFN, because the gun refuses to function with it.

You can hear/feel the difference when dropping the slide. With any other ammo, the gun snaps into battery with one *clack*. With the FMJTC, it seems to hang up slightly, and there are two distinct sounds and shocks, probably as the round is hits the walls of the chamber, changes angles, and is slammed home. It also has the delightful effect of hanging up, literally, every other round.

The fail to feed takes the form of the slide sitting slightly out of battery, with the round jammed between the top wall of the chamber and the feed ramp. A smart tap on the bottom of the magazine will cause it to chamber every time. A straw poll of other shooters ("here, shoot this and tell me what happens") indicates that it is not limited to my weapon.

In the interests of science (and making sure that it is the ammo, not my sidearm), I ran several more boxes of other stuff. The gun ran fine. I then tried another magazine of FMJTC.

*BOOM*

*Curse*

*Tap*

*Click*

*BOOM*

*BOOM*

*Curse*

*Tap*

*Click*

*BOOM*

And so forth, and so on. Out of 16 rounds, 7 failed to chamber without an assisting tap.

So, if you own an M&P40 and are looking for cheap plinkiing ammo, DO NOT buy Fiochi 170gr FMJTC. The FMJFN runs like a top, and so does CCI Blazer and Federal HST.

2. Now...I'm doing a round count and malfunction history. It doesn't seem right to just exclude the failures with the bad ammo, but I insisted on running through two boxes of it, out of sheer stubbornness and curiousity. That is also hardly fair ("here...this ammo clearly isn't working with the gun, let's shoot several more boxes and add the poor results to the statistics"). I think I'll leave it off the list, I'm just curious how to annotate it. As of right now, I'm just going to add a line mentioning the failures. Does anyone have a better suggestion?

Mike
 
I've had trouble with this ammo in other calibers and guns.

But thanks for the heads up, I won't feed my M&P any:D

I've been feeding mine the Winchester rounds that you buy in bulk at Wally World, havn't had any problems with it yet. As for defese loads I've used the Winchester Ranger HP a few times at the ranges it fed fine, too expensive to shoot a lot of it though but I'll count on it if the time ever comes. I've also fed it a few boxes of S&B and it ate that up like pie.

I would certainly chalk this experince up as "bad ammo" I wouldn't blame the gun until it starts happening with multiple ammo brands.
 
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It's the shape of the bullet. I have the same problem with the Ranier plated bullets; they are too long/wide to feed properly in my M&Ps.
 
Fiocchi works fine for plinking and practice in most of my handguns. And I agree, it is the shape of the TC bullet. It is subtly different from the FN.

Mike
 
Nwilly I'm with you Winchester White Box and Winchester Ranger 155gr HP's. 22 bucks for a hundred flat nose and 15-18 bucks for fifty hollow pionts.
Why no Winchester in your functiontest Coron?
 
Because I was able to get a large chunk of Fiocchi and Blazer, dirt cheap. The HST is my duty ammo. Once the Fiocchi and Blazer dry up, I will probably end up using something else.

Mike
 
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