Dumb question

F

fastlane

New member
You can shoot 22 shorts in a 22 LR, you can shoot 38 in a 357 magnum. Can you shoot 380 in a 9mm? The reason I'm asking is that I have a P238 and P938 and the 380 cartridges and 9mm look almost the same. I was wondering what would happen if I made a mistake and loaded a 380 in the 9mm? :confused:
 
Its happened before...

The round headspaces off the extractor, and it recoils oddly. Probably not dangerous per se, but not recommended... or good.

Switching them up the other way will result in the round not fully chambering. The gun may or may not fire like that depending on the disconnector design. If it does, that is very bad, as the case is not supported, and the timing will be screwy so lots of burning powder in your face and most likely a blown case.
 
Having never tried it.

357/38 in a revolver and 22 Short/LR in a revolver/bolt action rifle. But, .380 in a 9mm semi auto pistol, probably won't cycle properly due to the lower recoil energy of the .380 vs 9mm. Also it won't fit the mag properly and the extractor won't hook the rim properly. Sounds like a really bad idea. :eek:
 
Give it a try, we'll hold your beer.
Seriously, if all you had was a 9mm pistol and .380 ammo, and the zombie herd was heading your way, it would probably do.
Otherwise it's a less than good idea.
Although there are folks who shoot 9mm ammo from .38 Super pistols and seem to get away with it.
I ran across a fellow at the local range who got into the habit when he couldn't find sutiable ammo for his .38 Super 1911.
As I was also shooting a .38 Super that day, I offered him some of my reloads.
He politely refused (some people have no faith), and continued using his 9mm ammo.
No bad things happened.
 
Although the 380 is thought of as the "shorty 9mm" it's not really. Couple of thousandths in bullet diameter may or may not make a difference, but the different case lengths--and the fact that one slightly tapers will most of the time be problematic. I've read where people have switched off in the same weapon and successfully shot them both--but I think eventually the design dissimilarities will catch up with the habit.
 
marine6680 said:
Its happened before...

The round headspaces off the extractor, and it recoils oddly. Probably not dangerous per se, but not recommended... or good.
Click to expand...
Yes ... but.

The .380 case will (usually) headspace on the extractor in a 9mm chamber, as marine6680 has noted. But the 9mm Luger case is tapered, and the .380 ACP case is straight -- and very slightly smaller. I've done it, for experimental purposes. The round went off, but the smaller case didn't expand enough to properly obturate. I did it in a 9mm 1911. The slide didn't cycle, and the brass was so badly bulged that it couldn't be resized for reloading.

What I finally had to do for the purpose I was investigating was buy some 95-grain bullets (intended for .380 ACP) and load a box of 9mm cases to .380 velocity. Even then, the lighter loads wouldn't cycle a 1911 using the standard 9mm recoil spring. I had to reduce the recoil spring by several pounds to get it to cycle.
 
The .38 ACP/Super is supported ("headspaced") on its semi-rim. 9mm Parabellum can sometimes work in a .38 ACP/Super or 9mm Largo chamber because the 9mm P is tapered and will wedge itself into the chamber, but it depends on the tolerances of that brand or even lot of ammo. It cannot be depended on.

As to .380 ACP (9mm Kurz) in a 9mm P chamber, the .380 will usually be pushed too far into the chamber for the firing pin to reach the primer. Depending on the gun design, though, the .380 might be caught by the extractor and held enough to fire. Again, though, it is not something that can be depended on, and even if the .380 fires, it will probably not function a pistol chambered for the 9mm P.

Jim
 
I have tried to fire 380 in a 9...not intentionally and worse, my wife was with me, complaining of the gun she was shooting not working.

I was bouncing between a 380 and a 9 and got the ammo confusds when I was reloading the gun she was using.

The 380 cartridge fired, but the rounds didnt chamber. Took me a surprisingly long time to figure out the problem.

No damage to the weapon, but not a good idea to get the rounds confused.:rolleyes:
 
shoulder

This is just a theory, but I think there would be a hazard shooting high volume 380 Auto in a 9mm luger pistol. If by chance all the 380's headspaced off the extractor the brass would have some empty space in front of it where the case mouth of a 9mm would normally make contact to headspace. Hot gasses and friction from the round could slowly wear away at it. Or in a more immediate hazard, plently of soot would accumulate where the 9mm luger typically headspaces and switching back to 9mm could cause failure to chamber as the case mouth does not have a clean surface to press against. I have seen videos of someone shooting 40 cal out of a 10mm barrel which is a similar dilemma and the fellow didn't recommend it to others but since it had given him no troubles yet he decided to continue.

I just recalled another counter-argument. I cannot remember where I read this. The theory goes that if the round is able to slide forward in the chamber, pressure will build in the cartridge like normal upon ignition. However if the brass is not pressed against breech face (where the firing pin comes out of) the primer has room to leave the primer pocket to some degree and allow for a kaboom.

All in all like others I wouldn't do it regularly. I sometimes venture out and experiment while reloading with very light loads etc, but they are novelties and nothing useful for serious practice, and nothing I feel comfortable handing to family or friends to try as most of them are trying to learn to shoot as well.
 
I've experimented enough with 40's out of a Glock 10mm to say it'll work in an emergency. If you've got a G-20 and only 40 S&W ammo it is better than throwing rocks. Won't say what another brand will do.

I've got about 100 rounds down range with perfect function and no difference in POI on target. Not something I'm sure I'd do long term, but I've read of others who do. I tried it out of curiosity and it works. Never attempted 380's out of a 9mm.
 
Rimed 9MM, .380?

no.

the 9mm head spaces on the cartridge rim, as does the 380. so it might fire, but not safely.
Click to expand...
I must have a strange 9MM...it head spaces off the mouth of the case and seems to be rimless.:rolleyes:
 
Thanks everyone for the very thought out answers. I don't plan to fire any 380 in a 9mm or vice versa. I'm a old S&W model 10 and 15 guy with a couple of new toys to play with. These are the questions you get when a revolver guy strays from what he knows. :)
 
Reading through the thread, I imagine you're more confused now than you were when you started. Answers seem to have ranged from "NO! It's dangerous" through "It won't work" all the way to "It sort of works but it's not a great idea."

Now what? :) :cool:
 
If you mistakenly fired a .380 round in a 9mm gun.....it means you're breaking one of the cardinal rules of ..."only one kind of ammo on the bench at a time ?....

( put the .380 ammo away in the range bag / then get the 9mm on the bench )...
---------------------------
It might be ok ....or it might not....no real reason to find out !
 
If you mistakenly fired a .380 round in a 9mm gun.....it means you're breaking one of the cardinal rules
Click to expand...

9mm and .380 is easy to mix up. I've even made the mistake of putting .380 loose rounds in a 9mm ammo box. I think one of the cardinal rules should be: own .380's or 9mm's, but never both. I never had this problem before I inherited a .380.
 
9mm and .380 is easy to mix up. I've even made the mistake of putting .380 loose rounds in a 9mm ammo box. I think one of the cardinal rules should be: own .380's or 9mm's, but never both. I never had this problem before I inherited a .380.
Click to expand...

I frequently shoot both 380 and 9mm and I save the 9mm brass for my son-in-law. I pick up everything and I have to put them all on a table so I can cull out the shorter 380s. They are very close.
 
I guess I've been breaking a lot of rules. I have both calibers, and between my wife and I we often have both calibers out at the range. When they are intact it isn't hard to tell them apart at a glance due to overall length and, at least for the bullets I use, the ogive. In sorting brass, standing them up to sort them by height is fast, but I err once in a while.
 
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