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To: MileHi

No, and the reason why is how the cartridges headspace in their respective chambers.

Revolver cartridges headspace on the rim (or, more precisely, the front edge of the rim).

A semi-auto case like the .40 or 10 headspaces off the front edge of the case mouth. This means that the .40 has nothing but the ejector hook holding it from headspacing too far forward into a 10mm chamber.

The .40 killed the 10mm, mostly because the only difference between the 10mm and .40 is achieved by loading the 10mm to its real potential, which is well above what the .40 achieves, and high enough to cause some 10mm pistols to start developing issues like frame/slide cracks, etc. As a result of the ferocity of the full-house 10mm, the FBI down-loaded the round to give the ballistics of what became known as the “FBI load” in the 10mm, and that in turn fostered the .40 S&W when Smith noticed “hey, that load leaves all this unused space in the 10mm case, so why not just cut down the case, and we get a smaller grip size and we can double-stack it?” Lo, the .40 resulted.

The only solution (real solution) I would see to cycling a 10mm auto with a .40 S&W cartridge would be to obtain another un-chambered barrel for the 10mm auto pistol, and chamber it for only the .40, and then you’d be off to the races.


19 posted on 05/24/2014 10:53:58 AM PDT by NVDave
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To: NVDave
A semi-auto case like the .40 or 10 headspaces off the front edge of the case mouth.

I should have known that. Thanks.

The 10mm seems a bit much for most uses. I recall the same issue with the .41 mag. There were full boat hunting loads and a reduced load. Police who tried them mostly used the hunting loads in their duty guns and didn't like the .41 becuse of it. A good idea that never caught on.

24 posted on 05/24/2014 11:12:36 AM PDT by MileHi
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To: NVDave
"The only solution (real solution) I would see to cycling a 10mm auto with a .40 S&W cartridge would be to obtain another un-chambered barrel for the 10mm auto pistol, and chamber it for only the .40, and then you’d be off to the races."

I had the same thought. Colt also made the 1991A1 in .40S&W. I tried playing around with various components, mags, barrels, recoil springs, extractors, etc., but could never get the .40 to feed reliably from the mag, best case scenario, usually at least one stovepipe of per magazine. I was hoping to have a 10mm/.40/.357 Sig combo set up with the same slide and frame, but abandoned the idea when I couldn't get the .40 to work reliably.

33 posted on 05/24/2014 12:35:47 PM PDT by Joe 6-pack (Qui me amat, amat et canem meum.)
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To: NVDave

I’d buy a couple 10mm to 40 conversion barrels for my S&Ws and Colt. I’ve read reports of some shooting 40s in heir Springfield 10mm Omegas but am not interested in doing so.


44 posted on 05/24/2014 3:30:43 PM PDT by mcshot (..."And this too shall end.")
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