Disclaimer - it wasn't me. /Shaggy

 

Was sitting here sorting some range pickup brass and pulled these two funny looking buggers out of the pile. I wonder how many rounds this fella lit off before realizing he was shooting 9's out of his 40. Think they'll resize?

 

I didn't realize a 9mm cartridge would get retained in a 40 magazine. Someone lent me a mag for my 9mm CZ once and accidentally handed me a 40 cal mag and it was immediately apparent when the ammo wouldn't stay put. I guess they could have used 9mm mag in a 40 cal gun.

 

Wow I am pretty sure glock .40 mags can retain and cycle 9 or was it .40 mags can cycle .357

40 magazines can also retain and feed 357sig in most magazines.

My 9mm 1911 came with 45 acp mags. worked fine for 8 out of 10 rounds. Depends on the feed lips.

You sure that's not just glocked brass?

9 will feed in a 40 but not reliably unless you alter the lips. he probably kept getting double feeds and could not figure out why.

How can you load up your magazines with ammo that looks like that, and NOT realize it???

wow. there is a noticable difference in the size of the casing tho. How could he not inspect his brass and realize the problem.

You sure that's not just glocked brass?

You may be onto something. Not only did he load the wrong caliber, but he loaded them backwards so they bulge at the mouth! So then i suppose the shell gets gets fired and the bullet gets ejected? =@

How can you load up your magazines with ammo that looks like that, and NOT realize it???

It wasn't loaded this way, the appearance of these shells are a result of firing a small cartridge (9mm) in a chamber much larger (.40S&W) and so the brass expands to the dimensions of the larger chamber. In the rifle world, this is actually a viable method to convert some caliber of common brass to a more obscure derivative of it and its called "fire forming". In fire forming, the dimensional difference is usually limited to expanding the case mouth or reshaping the shoulder, both a very marginal percentage, never ballooning the case body though (AFAIK).

It wasn't loaded this way, the appearance of these shells are a result of firing a small cartridge (9mm) in a chamber much larger (.40S&W) and so the brass expands to the dimensions of the larger chamber. In the rifle world, this is actually a viable method to convert some caliber of common brass to a more obscure derivative of it and its called "fire forming". In fire forming, the dimensional difference is usually limited to expanding the case mouth or reshaping the shoulder, both a very marginal percentage, never ballooning the case body though (AFAIK).

Fire forming is not done with a bullet in the case, rather paper or bread is used as wadding.

I wonder how many rounds this fella lit off before realizing he was shooting 9's out of his 40.

 

Probably one round. Everytime I've seen this happen the gun will usually lock up as there is not enough extractor in the groove. I've seen 9mm rounds loaded and retained in Glock, S&W and H&K 40 mags. I can't speak for other manufacturers.

 

40 magazines can also retain and feed 357sig in most magazines.

 

No wonder as the 357 SIG is based on a necked down 40 case.

 

Fire forming is not done with a bullet in the case, rather paper or bread is used as wadding.

 

My experience with fireforming dictates the use of a bullet with a reduced charge. The reason is is pressures would build up sufficiently to form the brass without a bullet giving some resistance.

 

You may be onto something. Not only did he load the wrong caliber, but he loaded them backwards so they bulge at the mouth! So then i suppose the shell gets gets fired and the bullet gets ejected?

 

Jon, come on this wasn't a serious answer was it?

Interesting! I've seen a newbie shooter at a range put a few .40's through a .45 1911. Similar bulging, but no damage to the pistol.

Probably one round. Everytime I've seen this happen the gun will usually lock up as there is not enough extractor in the groove. I've seen 9mm rounds loaded and retained in Glock, S&W and H&K 40 mags. I can't speak for other manufacturers.

There were two in the pic alone, not sure how many were still lying in the dirt undiscovered.

 

You may be onto something. Not only did he load the wrong caliber, but he loaded them backwards so they bulge at the mouth! So then i suppose the shell gets gets fired and the bullet gets ejected?

 

Jon, come on this wasn't a serious answer was it?

Come on, of course i was being facetious!