.40 through a MK23

[MaD HuNGaRIaN]

Ok, so at the range today, the genius behind the counter gave me a box of .40 when I clearly asked for .45 ACP (yes, I said "forty five ACP" when I asked for it).

So, I loaded up my mags, and this particular .40 from magtech didn't have a flat nose, and I had been shooting 9mm for so long, that it was sufficiently bigger, that I didn't give it a second thought.

I will never not double check what they hand me ever again.

I knew something was amiss when the shot was 2" off the mark and tumbled like mad. The gun didn't cycle. The brass was ruptured up the sides, but extracted cleanly.

I had the smith look at it and clean it up, and everything seemed fine, nice tight groups.

What is the potential for damage to the barrel if it is bouncing around in there on the way down? Not to mention being 10,000 psi more pressure? (Albeit with little to no resistance.)

[I want a Mk23]

I've done that a few times with a 1911, and a few times on purpose just to prove it would work. Still no damage to the gun...or myself, yet. I was using 9mm though.

[Hired Gun]

I just went a got a .40 round...it falls all the way through the barrel. No way I could accidentally do that because it wont chamber, but this is a USP. I would think the barely dimensions would be the same at the chamber.
I have loaded .40 in a .45 mag by mistake though.

[SIGtrarian]

What is the potential for damage to the barrel if it is bouncing around in there on the way down? Not to mention being 10,000 psi more pressure? (Albeit with little to no resistance.)Zero potential for damage. That is totally harmless. Google "fire forming brass". Cases for many wild cat cartridges have been formed in a similar manner.

[heffa]

I just went a got a .40 round...it falls all the way through the barrel. No way I could accidentally do that because it wont chamber, but this is a USP. I would think the barely dimensions would be the same at the chamber.
I have loaded .40 in a .45 mag by mistake though.

If the extractor grabs the rim of the case I could see it firing. I did do this once with a 1911 (loading the mag and having a conversation at the same time) when I let the slide down with the gun pointed at the ground the round slid threw the barrel and hit the ground, the trigger was never pulled. Lesson learned!

[rext]

Had a cousin do that with a Sig 220,his duty gun.He had gotten a bunch of loose ammo to shoot up and a couple were .40.No problems though.

[G3Kurz]

Check the barrel for the presence of a bulge or ring inside the barrel. Unlikely in the scenario you described but be sure. If a live round had slipped into the bore as is common with 9mm's in .40 and 10mm firearms a ring or bulge is common.
Now of course it was the genius who sold you the .40 S&W ammo for a .45 but a rocket scientist was the one who actually loaded and fired it! :)
G3Kurz

[MaD HuNGaRIaN]

Now of course it was the genius who sold you the .40 S&W ammo for a .45 but a rocket scientist was the one who actually loaded and fired it! :)
G3Kurz

Indeed, lesson learned. :90: