What happened is obvious, but surprising!

[pert near]

I have a good friend that is a police officer & every so often he brings me some brass from the firing range. The mix of brass is about 70% 9mm, 20% .40 SW, 10% .45 ACP. He pointed out that with advances in the guns & ammo, a lot of officers are switching back from their 40's to 9mm. I was de-capping & tumbling some brass when I found this case. Unfortunately, it was already de-capped & tumbled when I found it while doing my QC. I don't know what the primer looked like.

It seems obvious, someone fired a 9mm in a .40 S&W pistol & it DID go off! Don't know more than that, but interesting none the less.

 

[Corpral_Agarn]

I've seen 9 shot from a 40.

But that is someone not paying attention

It's only 1mm difference

 

[Hartkopf]

Resize it and move on.

 

[sequins]

I hear if you use a makarov ring you can bulge bust that with a lee die

 

[entropy]

I find those at the range all the time; I've also found .308 fired in either a .30-06 or .35 Whelen.

 

[ApacheCoTodd]

Hell, who DIDN'T see this coming when they developed the 10mm kurz?

Doesn't happen in a REAL 10mm.

Todd.

 

[Olon]

Wow that Glock bulge is truly pernicious to the reloader...

 

[ApacheCoTodd]

Wow that Glock bulge is truly pernicious to the reloader...

And here, I thought it was that dreaded future downfall of Western Culture.... The *unsupported* Colt chamber!

Todd.

 

[Rock185]

I haven't managed to do 9MM in .40 myself, but have seen it. Also seen .308 brass obviously fired in .30-06, etc. chambers.

 

[Demi-human]

It's only 1mm difference

But it looks like a lot more!

 

[tightgroup tiger]

I find them at the indoor ranges too. It's hard to believe that brass can stretch that far.
It's harder to believe that people are so stupid they make that mistake or their to ignorant to care.
I'm also glad the walls between the lanes are bullet proof.

 

[1KPerDay]

I finally did this the other day. I've been swapping .40 barrels and .40-9 conversion barrels out of my G22, working on accuracy issues etc.

Chambered a 9mm, took aim, (pop)... thought it was a squib. Ejected the case, examined it, felt like an idiot... looked just like the one above except it was split as well.

Stripped the barrel, looked for squib, clear. Walked down range, and the bullet had hit absolutely dead center on my 1/2" black pasty dot. Best shot I've ever fired from this pistol, or any other. LOL

Maybe I should just shoot 9mm out of my .40 barrel (kidding).

 

[Walkalong]

People do it with .40 in .45 as well, see them at the range from time to time.

 

[SSN Vet]

I believe your analysis of the root cause is incorrect....

This is what you get when you leave a 9mm round and a 45 round in the same ammo box without a chaperone.... that's a 9mm baby bump

 

[jmr40]

I used to own both a G23 and a G19. Had them at the range and stuck the G19 magazine in the G23 by mistake. The round didn't eject, but the case looked just like that.

 

[zaitcev]

Better this than 300BLK ammo in a 5.56 gun. It should not chamber in theory, but if you whack the forward assist hard enough, you can do it. Frankly I would only build 300BLK uppers with flat side receivers just for this reason.

{Update: Someone pointed out that I got that backwards: it's the 5.56 uppper needs to have the forward assist removed for safety. So much for that idea. I guess we're back to putting electrical tape on magazines.}

 

[entropy]

It would make more sense to build your 5.56/.223 uppers with flat side receivers. A .223 does not need to be 'whacked forward' to go into a .300BO chamber.

 

[Aim1]

I find them at the indoor ranges too. It's hard to believe that brass can stretch that far.
It's harder to believe that people are so stupid they make that mistake or their to ignorant to care.
I'm also glad the walls between the lanes are bullet proof.

Shoot, when you have 20 cops who are told to load up fast and have loose rounds of 9mm, .40, and .45 I can see it easily happening.