Son and I ran out to Birchwood tonight to do some shooting. Grabbed my S&W M&P .45 and some factory ammo that was laying around so we could entertain ourself as our rifle barrels cooled down.

After about 50 rounds through the .45 I heard a dull "pop". This alarmed me so I pulled back the slide and noticed the case was still stuck in the chamber. Luckily I always carry a .22 cleaning rod so I inserted the rod in the muzzle and popped out the case. What I found was a 40 S&W case. The bottom third of the case looked normal but the top 2/3rds expanded and split to fit the .45 chamber. To be honest I was shocked it even fired.

Have no idea where the .40 round came from. I do have a Glock .40 but it hadnt been to the range in years. Guess I will look a little closer when I am loading the magazines in the future. First time in my life I ever fired incorrect ammo in any weapon.

Might add I have run about 500 rounds thru this pistol in the last couple of months. All bullet weights, shapes and sizes. Not one failure to feed or eject until the .40 round. Super reliable pistol and very accurate to boot.

One senior officer who I worked the range with brought his son to requalification one year. During a lull they took off down range to shoot a few rounds with our issue 10mm S&W 1006 pistol. I heard several loud kaBoom! then a kwong!?. Mutter, mutter snick snack kwong!? Hey Rick WTF!

Seems the son had grabbed a box of 9mm rounds that we had for the MP-5's and then somehow loaded them in the magazine. They wouldn't cycle the slide and the expanded cases lookes like the old .41AE round.

Later the local PD bought into the new .40S&W round for their new duty pistol and we tried some in our 10mm pistol and they worked! Everytime, probably not a good idea but we found that we could use their ammo if the need arose.

I sure the case was held in place by the extractor allowing the fireing pin to hit the primer.

...p dog shooter
one of us
Posted 07 August 2009 05:25 Hide Post
I sure the case was held in place by the extractor allowing the fireing pin to hit the primer.
Posts: 4814 | Location: wis | Registered: 21 April 2001

......exactly