40s&w in a 10 mm...

[TAB]

So I just got done tumbling my 10mm brass and noticed I had a few 40 S&W cases.   It got me to thinking, lets just say I was asleep at the switch and reloaded these. If  they some how managed to actually make it to the delta elite, had a good prime strike and went bang... what would happen?


I'm thinkling maybe a squib do to lots of unburned powder, do to lack to bullet seating depth...

Any ideas?

[ismram]

I would bet that the bullet exits the gun. Hard to guess what happens.  I wouldn't do it on purpose!!

[Mojave Desert]

I remember an article in a gun-mag a few years back where the author chambered some .40 S&W factory loads in a 10mm and fired a few off.  The extractor had to hold on to the cartridge so the firing pin can whack the primer.  I remember the article said the gun fired ok enough, but the accuracy really suffered.
 
Now, if you put 10mm worth of powder in a .40 S&W case, then load up, all bets are off.  Bad things are very likely to happen.\

Just be careful in sorting out the brass.  Luckily it's easy to tell between .40 S&W and 10mm.

[Trevor]

I am mildly surprised that no one has said it yet, but I will: Never fire a cartridge in a firearm for which it is not chambered. Safety first, scouts.  Regarding the 10mm Auto versus the .40 S&W, there was, once upon a time, the Peters-Stahl multi-caliber conversion pistol with dual extractors that provided strong enough tension for proper headspacing to switch calibers.  These units though never caught on.  There is also the interesting S&W 610 revolver that, per the manual, can use .40 S&W cartridges because the moon clips help provide proper headspacing.  Other than these two examples, don't do it.  Inspect your brass and finished cartridges when reloading.