.40 Shield Kaboom

Oh no, I don't have 2.5mm of exposed brass casing as shown. That to me, would be unacceptable. My unfired Shield 40 has more like .5mm which I hope and believe will be OK with factory ammo.
 
^^With an empty case chambered and my thumb on the primer to keep it properly head spaced, I stuck a sewing needle up the feed ramp and scratched the surface of the case as deeply as I could reach. The deepest scratches were 6mm from the breach face and 2.5mm from the barrel face. It is deceptively deep, but you can tell that it is still in the region where the case wall is thickened.
 
If you think this only happens to S&W guns then Google "Glock failures" or "1911 failures" or insert your favorite manufacturer followed by "failures". This Shield did not fail because of an unsupported chamber. It failed because of a bad round of ammo. And in the end, it really didn't fail. It did what it was designed to do under that condition. It is possible that the round was double charged. It is also possible that during the chambering process, the bullet was pushed father into the case which would cause a high pressure situation. Almost all guns have a certain amount of "unsupported" brass when a round is chambered. With normal pressure the modern brass case is designed to hold up in the area that is unsupported. That area of the chamber where the brass is "unsupported" is necessary to allow the round to make the transition from the magazine into the chamber. It is also a path for the gas from an overpressure round to escape from the gun allowing the pressure to vent away from the shooters face. The reason that the Shield has what appears to be a larger unsupported area compared to full size guns is that the geometry of the barrel is different because it is shorter. Don't think that the engineers who design guns don't know about this and don't think that the manufactures are negligently sending guns with safety design flaws out to the market.
 
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emory said:
^^With an empty case chambered and my thumb on the primer to keep it properly head spaced, I stuck a sewing needle up the feed ramp and scratched the surface of the case as deeply as I could reach. The deepest scratches were 6mm from the breach face and 2.5mm from the barrel face. It is deceptively deep, but you can tell that it is still in the region where the case wall is thickened.
Click to expand...

I'm trying to visualize this. So, the take away point is, dangerous? Shield 40 chamber prone to allow KaBooms more often than we'd like with factory and/or properly loaded ammunition?
 
I have confidence that the chamber support of the Shield in .40 S&W has been fully tested and is more than adequate for all new brass loaded to produce pressures within SAAMI specs.

However, there are other (typically larger) semi-autos in .40 that have more fully supported chambers and may be more appropriate for shooting reloads or hot boutique rounds.
 
I had a 9x21 and later a 9x23 1911. On one of them my cases were routinly bulged. I even had a "super face" round once (super face is when the round goes kaboom in the gun). It was during competition. The range officer stopped me. I had no idea what happened. I just knew that my mag got blown out, my medallions on the grips went zinging and there was a lot of gas leaking out of the grip area. Everyone hovered around me and was asking me if I was ok. I didn't understand what a big deal this was. Both the gun and myself were fine. I still have the gun and it still shoots wonderfully. The barrel has been changed back to a reg. 9mm though.
 
Guys, please, if you want a high pressure load in an unsupported chamber then go look at pretty much any Colt Delta Elite in 10mm. All these kabooms happen from some kind of ammo fail. Either the bullet was setback during the jump from the mag to the chamber due to poor neck tension, an overcharge of powder, or something else similar. The case being supported is not going to stop any of these events from happening.
 
emory said:
I have confidence that the chamber support of the Shield in .40 S&W has been fully tested and is more than adequate for all new brass loaded to produce pressures within SAAMI specs.

However, there are other (typically larger) semi-autos in .40 that have more fully supported chambers and may be more appropriate for shooting reloads or hot boutique rounds.
Click to expand...

I agree. Smith and Wesson spent a large amount of money and resources to assure that their gun would handle ammunition within the specifications that it recommended. Faulty manufacturing techniques, intentional overloading, bullet setback, or re-use of compromised cases can all produce ammunition that exceeds these specifications. Assuring safe operation then is impossible.

I don't know that even a chamber with more support would render a gun totally immune to the hazards of too high pressure. Excess pressure has to go somewhere. Maybe the next step would be a ruptured chamber itself.
 
Maximumbob54 said:
I'm still picking up my Shield in .40SW tomorrow afternoon.
Click to expand...

And I just picked it up.



That's Winchester 180 JHP in there and I think it's supported just fine. No, it's not fully supported but it's plenty enough unless I'm asking for trouble with my reloads. And once again, my Delta Elite has a lot less chamber support for a 10mm...
 
Congrats! Good pic! Yep, sure enough. A picture is worth a thousand words.
 
glad to hear your peepers are intact. one more reason to like heavier, but a little less prone to failure, steel. i got rid of my shield after the first 5 or 6 stories i heard and saw remains of... glad your ok. .40 has a reputation for destroying polymer guns. glock comes to mind.
 
Abacus said:
I have heard that Winchester White Box has had some QC issues lately. I suspect what happened to your Shield 40 was an ammunition issue. I wonder if the unprecedented high demand for ammo has resulted in quality control issues. I have attached a link that shows another gun (AR15) that was also blown up using WWB.



https://www.facebook.com/TacticalResponse/posts/759178560778722
Click to expand...


That link shows USA Ammo (commercial remanufactured) caused the issue. That is not WWB.

Let's not forget that OP still hasn't returned to share pics of the Ammo / Lot # in question, and the last .40 Kaboom blamed on factory ammo was actually found to be a result of reloads.

Were all speculating without much actual info here - that bears repeating.
 
It's easy to confuse USA Ammo with Winchester USA Ammo. How did they get away with naming their company USA Ammo? Didn't Winchester have the rights to that name just like Remington has the rights to UMC?
 
I was just watching a great YouTube video by Mrgunsngear entitled, "40S&W to 9mm Shield Conversion" in which somebody made a comment, "My Shield 40 blew up on me and S&W did nothing to help me."
I then asked him, "Was it hot reloads you were shooting?"
He replied, "No. Federal."
 
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