short and weak in the long and strong

[siberian505]

My buddy Wally was messing around the shop today, emptied my G20 and reloaded the magazine with 5 40 S&W's Went out and shot them in the plate. Has anybody tried fooling with 40 cases in a G20? I am going to town and gonna pick some once fired 40's, load them with WC 820 and a 174 grain SWC(Magma 170 gr) . might be a fun load playing in the hills, just shoot and leave the brass.

[The_Shadow]

siberian505, while the 40S&W does chamber and fire from the 10mm chambered barrel it can cause issues...
Shooting the shorter cartridge doesn' allow for proper headspacing other than the extractor...
The striker can actually knock the casing out from under the extractor and it will go inside the chamber.  The casing is now loose and will not clear by racking the slide if that happens.  Bad mojo in a defensive situation.
While shooting bullets can shear off tiny bits of jacket, lead/alloy on the end of chamber cut...
Also the bullet has a longer jump to the rifling, the drop in pressure can cause poor burning characteristics causing excessive sooting/fouling...again not conducive to reliable feeding.  Also think of 38's in a 357 Mag gun, the carbon ring can cause chambering issues for the longer cartridge if not properly cleaned after the use of the short cartridges.

The better solution is to get the aftermarket 40S&W chambered conversion barrels! 

[sqlbullet]

This article goes into detail, with photos about why this is generally a bad idea.

[siberian505]

I am going to seat the bullet out, should be able to make a round at 1.250 with the three cast bullets sitting on my loading bench.

[DM1906]

I do it all the time.  Thousands of rounds.  It won't hurt anything, not one thing, just heed the warnings.  DO NOT rely on if for defensive purposes (unless that's your only option, of course, which may be a handy option).  Always clean the chamber afterward.  Pay close attention to the ring of stuff that will accumulate at the forward chamber cut.  Use a scribe to ensure it's clear and test with a 10mm cartridge (drop one in while the barrel is out, it should fall in to chamber depth, not bind, then fall out) before putting the iron back on duty.  No different than target shooting .38's, before putting the .357's back on duty (or .44 spl/mag, .45LC/.454/.460, or whatever).  Using .40's in the 10mm chamber does require headspacing by the extractor, so if it doesn't eject, have a rod handy to push it out.  I have only one revolver that's "spl only" (mod. 12 Airweight), but all the rest get a healthy diet of all that fire in them.  The 10mm is no different.  A bonus is all the .40 brass falls within a 3 foot circle where I'm standing.  The Blackhawk 10mm is different, though, as it doesn't have an extractor.  Working on a fix for that one, now.

[The_Shadow]

DM1906
Using .40's in the 10mm chamber does require headspacing by the ejector, so if it doesn't eject, have a rod handy to push it out.

Not a jab or dig...but the proper term is extractor, not ejector! 

[DM1906]

DM1906
Using .40's in the 10mm chamber does require headspacing by the ejector, so if it doesn't eject, have a rod handy to push it out.

Not a jab or dig...but the proper term is extractor, not ejector! 

Oops!  Fixed....

Guess that's evidence of two things.  I'm human, and someone actually reads my dribble.  Thanks for catching that!

[The_Shadow]

Just keeping it real!  We need to be a step ahead of the lower caliber!  LOL 

[Turo]

I've only fired 3 rounds of .40S&W out of my Glock 20 with 10mm barrel, and out of those three, two of them fired fine, and the third round's primer punctured and spit gas and dirt into the firing pin channel.  I can't say it's dangerous to do, but it definitely throws powder residue in places it's not supposed to be and has erratic ejection.  It'd probably work in a pinch, but a .40S&W conversion barrel will pay for itself in under 1000 rounds and works much more reliably.

[REDLINE]

Yeah, if it works for some, fine............but for me, 40 in my 10s would only occure in a pinch.  Heck, if I ever get into a pinch with zombies I'ld throw some 357SIG rounds in my 10s and hope for the best.