S&W Kaboom (56k Beware)

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Tom Servo

Staff
This is an M&P 340, Scandium-frame .357 J-Frame. The owner fired six rounds of .38 Special through it without issue. The first shot of .357 blew up the gun. The operator was unharmed, as all of the unpleasantness happened forward of the muzzle.

The .357 loads were factory ammunition, and quite mild. It wasn't an ammunition issue.

It appears that the barrel torqued fairly hard. The frame cracked beneath the forcing cone, allowing the barrel to come unscrewed by about 3/8". The barrel shroud sheared off. The actual barrel easily unscrewed the rest of the way.

So, I have to ask, is Scandium really feasible for this load, on this frame? This is the second failure of this material I've seen, and there are several other documented cases. As you can see in the third picture, the barrel (which is very light and thin steel) screws directly into threads carved into the Scandium.

Would a pinned-in steel bushing on the frame help, perhaps?

340_2_pc.jpg


340_barrel.jpg


340_forcing_cone2.jpg


340_crane.jpg


This is not a thread about how some people don't like S&W for whatever reason, so please don't take it there.
 
T

Tom Servo

Staff
Do you know what Smith & Wesson's response to this was?
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This happened about an hour ago. It'll be Monday before I can get in touch with them.

No doubt they'll cover it. I've had very good experience with their customer service.
 
O

Ozzieman

New member
WOW +1
It failed at the weakest point, that’s what your photos show, but man the metal at the break is VERY thin.
Is it possible that there is something wrong with the forcing cone?
Glad to hear you’re alright,,,, except for maybe your underwear,,,, I know mine would be “stained” after that.
 
B

Brian Pfleuger

Moderator Emeritus
According to this article, the term "scandium frame" is a significant misnomer. It's used in the name, essentially, only because it sounds "cool":


As a professional metallurgist who's developed strong aluminum alloys for 40 years, I'd like to clarify the term "scandium" as applied to certain strong, light, gun frames. Such "scandium" frames are not made from this expensive rare earth element with mediocre mechanical properties. Rather, the frames are made from strong aluminum alloys whose major strengthening elements include zinc, magnesium and copper, which may total more than 10 percent of the alloy.

Scandium is added only in small amount, perhaps about 0.2 percent, to prevent recrystallization of the aluminum alloy during high-temperature heat treatment, commonly applied at 850 degrees F or higher. Scandium allows the alloy to retain the fibrous, worked structure resulted from prior metal working processes, such as forging or extruding. This structure is stronger than a recrystallized structure and, perhaps more importantly, better resists the stress-corrosion cracking tendency inherent in certain strong aluminum alloys.
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rantingredneck

New member
YIKES.......:eek:

I've got to agree with Tom's question. Are we pushing the envelope when it comes to smaller/lighter/more power to the point of compromising safety?

I'm not really sure I'd want to shoot .357 magnum out of a properly functioning M&P 340 as that's just too light a weight gun for that level of recoil for my hand. That being said, with the materials involved it seems like the margin for error has just been whittled down to nothing. One minor mistake in assembly can lead to such drastic failure.
 
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dandydany

New member
Tom Servo, if you promiss not to bash my Hi Point, I won't bash your $900 S & W. They are real nice guns, I almost got me the light weight version in .45 ACP, but due to Ca. laws, could not get it ( not on the DOJ list of approved guns ). I also will not telll you what you should buy....;) Catch you later, Dan :)
 
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goodspeed(TPF)

New member
Will surely be interesting to hear what S&W has to say about this. It also will be interesting to see if there are many more such failures.
 
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xrmattaz

New member
I've heard/seen this before. As mentioned, it's likely due to overtorqueing of the barrel on assembly.

That said, my 329PD is still going strong, after several hundred full power .44 magnum loads, and several thousand hot .44 Special handloads.

(thank goodness for S&W's excellent customer service....they'll fix you right up)
 
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tekarra

New member
The fracture mode is difficult to tell from the photos, however it appears to be caused by a mechanical condition as you suggest. I would think S&W would like to have a look at your revolver.
 
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gglass

New member
looks like a Taurus to me.
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Yup....twice the price. Same results.
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The real difference between the two is this...

Taurus:
  • The Taurus would cost the owner shipping charges to an authorized repair center.
  • The Taurus would be at the repair center for weeks to months while waiting for a new barrel and or parts to arrive from Brazil.

S&W:
  • Smith & Wesson would send a pre-paid shipping label to have the firearm sent to their manufacturing facility, and would cost the owner exactly zero dollars.
  • The Smith & Wesson would be repaired or replaced in a matter of days as most on these forums can attest.
 
F

fprefect

New member
.357 barrel

When smaller frames and new lighter alloys are being but into use, in many cases with insufficient testing, to make handguns lighter, smaller, and more comfortable to carry concealed, while at the same time hotter ammo is being developed for these same weapons, occasional failures are certain to be the result. Not saying that was the case here, but cause will be identified and hopefully rectified.

F. Prefect
 
T

Tom Servo

Staff
Let's avoid the brand comparisons, guys. I just wanted to discuss the technical issues.

I've no doubt S&W will handle this gracefully. I'll be asking them detailed questions as the the how and why, and I'll update as I find out.
 
E

Edward429451

Moderator
So Scandium is really aluminum and they dance a jig around the truth of it?

An aluminum 357...hmm. Would you have bought it if it had been billed as aluminum frame?
 
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