Why does .380 not fire in 9mm guns?

[carguychris]

Originally Posted by jetinteriorguy

It’s refered to the 9MM short because the bullet caliber is still 9MM but the case is shorter than a 9x19/9MM Parabellum.

This is actually a common misconception.

The actual reason for the name becomes clear when you realize that its full European name is 9mm Browning Short, and that it is shorter in length than the previous two 9mm cartridges developed by John Moses Browning, the .38 ACP (aka 9x23mm SR) and 9mm Browning Long (9x20mm SR). "0" was added to ".380" and "Long/Short" was added to the two "Browning"-named cartridges to help people tell them apart. However, 9mm Browning Long is obsolescent and scarce, so many shooters don't know about it and hence don't realize that it's behind the "Short" nomenclature.

[bedbugbilly]

Both 380 and 9 are rimless that headspace on the throat of the casing - both different overall lengths - that's the first thing . . .

BUT . . I have witnessed the 380 being fired in a 9mm. A friend of mine had a Springfield 9mm - his wife has a 380 Sig. He is a little ADD at times and he got some of his wife's 380 mixed in with his 9mm. The the 380 certainly didn't headspace on the throat of the casing - BUT - the ejector/extractor held it back far enough that the firing pin fired it. So it is entirely possible . . . but not a recommended thing.

In general- the .380 usually uses a .356 bullet and the 9mm a .357 - however, it all depends on the individual pistol bore. I only shoot my own cast . . I have a 9mm that the throat easily takes a .357 - .358. Those may be too large for the majority of the .380 chamber throats - again, depending on the individual pistol - throat size, chamber depth, etc.
On the other hand, you can shoot a 38 Colt Short, 38 Colt Lng and a 38 Special in a 357 BECAUSE those are "rimmed casings" and the same case diameter, bullet size, etc. just different OAL.

[TailGator]

I took a friend shooting who was new to semis, and he called me over to ask why the pistol he was using, a Beretta PX4 9 mm, wasn't cycling. Turns out he had loaded .380 ammo when I wasn't paying attention (my bad). The ammo apparently head spaced on the extractor and fired, but it did not cycle the slide well enough to function. The ammo has a light bullet and small charge relative to 9x19 ammo, so that is what we would intuitively expect. But it does fire - or did in that pistol - it just converts a semi into a single shot pistol.

[ftttu]

I admit that I'm a big bonehead sometimes. I sold my first G42 to my sister in Houston, and when we were at the range there, we shot my new G43, the G42 and her PPQ 9mm. Well, after a few magazines of each, I loaded up some .380 in a magazine I assumed was a G42 mag. I started firing, and I immediately started having malfunctions. I was embarrassed because I had just sold her the pistol for her self protection, and I had just received it back from Glock for those first release problem fixes.

It fired accurately, but I just couildn't understand why it was intermittently cycling and stovepiping. Then it dawned on my I had been firing the .380s in the G43. I inspected the pistol, and it had no visible signs of damage.

Now let me tell you about that ND...

[jetinteriorguy]

That's why I stated it is "referred to" the 9mm short, not named the 9mm short.

[Aguila Blanca]

Originally Posted by jetinteriorguy

That's why I stated it is "referred to" the 9mm short, not named the 9mm short

But in Europe it is named (among other things) 9mm Short (9mm Kurz, or 9mm Corto).

[CajunBass]

I've never had any problem with the loaded cartridges, they're kept in boxes or bags when loaded.

I have swept up spent brass at the range and have gotten 380 mixed in with all the other stuff. In handful of 9mm, 380 just jumps out at me.

[jetinteriorguy]

OMG, my bad. Must have lost my head for a minute and forgot I was on the Internet. Next time I'm looking for .380 ACP I'll be sure to look for 9mm short to make sure I get the right ammo.

[Bill DeShivs]

Actually, much European ammunition is labeled 9mm Short, 9mm Corto. That ammunition is sold in the US.

[johnwilliamson062]

9mm short never seems to fit in my clip like 380 ACP does. Then it doesn't go into the barrel very well and I get mis-fires.

[Ledslnger]

Because the 9mm is superior.

[cje1980]

It actually most likely will actually fire in a lot of 9mm chambers. You'll end up with bulged casing and poor functioning though. The 9mm is a tapered case. The 380 is a straight walled case so it a smaller diameter near the case head. You could potentially have a ruptured case due to that. By the way. Before mixing bags of ammo. If you mixed 5.56 and 300 blackout and loaded a 300 blackout in a 5.56 chamber you are going to blow up your rifle.

[SDF880]

I managed to shoot 5 rounds of 380 out of a Glock 34 with no issues I won't say anymore!

[Cirdan]

I fired a whole magazine of .380 through my Beretta Nano once (9mm). Couldn't figure out why it wasn't cycling.

Fortunately that's the dumbest thing I've done with a gun.

[jetinteriorguy]

Hmm, never thought about it but can you actually fit a .300 BO round in a 5.56 chamber?

[Bill DeShivs]

No, you can't chamber the .300 in a 5.56.

[Aguila Blanca]

Originally Posted by Sturmpanzer

Might be a dumb question, but Ive heard the .380 called a 9mm Short, so why will it not fire in a 9mm pistol?

It's always best to stick with the cartridge that a particular firearm was designed for. Otherwise, be as specific as possible when investigating alternates, and don't be mislead by names that may be deceiving.

For example, .38 Special is not .38 caliber -- it fires the same .357" bullets that the .357 Magnum uses. The .38 Special dates from a time when the cartridge was named for the outside diameter of the case (.379") rather than the diameter of the bore or the rifling in the barrel.

There are too many "9mm" cartridges to make generalizations. As has been mentioned, the .380 Auto (or "ACP") is also known as 9x17. The 9mm Luger/9mm Parabellum is the 9x19. They both use basically the same diameter bullet, but the cases are different. However, between those two is the 9x18 -- a.k.a. 9mm Makarov. And the 9mm Makarov will NOT in any way interchange with either the 9x17 or 9,19. The 9mm Makarov has a larger case (.3915", tapering to .3904") and it fires a larger diameter bullet (.3650") than either the 9x17 or 9x19. But it's still referred to as a "9mm."

[JohnKSa]

Owner's manuals almost invariably provide information on the ammunition types that are safe to use in a particular firearm. Sometimes more than one caliber is acceptable (e.g. .38Special and .357Mag in .357Mag revolvers), but that is actually quite unusual in the overall scheme of things.

I am not aware of ANY autopistols where the manufacturer recommends/allows the practice of using any caliber other than the specific caliber that is stamped on the autopistol.

[TruthTellers]

.380 can be fired in a 9mm if the gun and ammo combination is right. I say that because I'm sure there will be some .380 out there with a hard primer and probably doesn't headspace quite right and won't fire, but for the most part I think most 9mm pistol will shoot a .380.

The question of safety is really up in the air. .380 is lower pressure than 9mm, so it's not like the barrel is going to do a banana peel from a cartoon, especially when the case is being formed to the 9mm chamber, which is about .015" larger in diameter. That means a lot of the energy from the gas expansion is going to go into enlarging the case, then when the brass swells and seals the chamber, the bullet will then be projected down the barrel, albeit at a lower velocity than if fired from a .380 chamber.

It's a lot like shooting .22 LR in a .22 Magnum. Some people do that regularly, but given that .22 brass is so thin and weak, I actually think it's safer to shoot .380 in a 9mm than .22 LR in a .22 Magnum.

I think if one wanted to shoot .380 in a handgun with a bore of around 9mm diameter, the best choice is a .357 Mag revolver. Plenty of strength in them and the case diameter of .357 is only a few thousandths larger than .380, the only issue is finding a way to headspace the .380. Moon clips are about the only option.

[TruthTellers]

Originally Posted by JohnKSa

Owner's manuals almost invariably provide information on the ammunition types that are safe to use in a particular firearm. Sometimes more than one caliber is acceptable (e.g. .38Special and .357Mag in .357Mag revolvers), but that is actually quite unusual in the overall scheme of things.

I am not aware of ANY autopistols where the manufacturer recommends/allows the practice of using any caliber other than the specific caliber that is stamped on the autopistol.

I'm sure .22 Shorts and Longs are acceptable in .22 LR pistols. I've shot .22 Short in some of my .22 autopistols just to see if it will feed the next round in the magazine. SR22 does fine in that regards, so it becomes a two shot affair.

The tip up .22's are cool because you can legit turn them into single shot derringers when shooting .22 Short.

[JohnKSa]

I'm sure .22 Shorts and Longs are acceptable in .22 LR pistols. I've shot .22 Short in some of my .22 autopistols just to see if it will feed the next round in the magazine. SR22 does fine in that regards, so it becomes a two shot affair.

The tip up .22's are cool because you can legit turn them into single shot derringers when shooting .22 Short.

Yup-I wasn't thinking about rimfire. I should have said "...any centerfire autopistols..."

[HisSoldier]

So you can fire .380 ACP outy of some 9mm pistols, but you won't be happy with the results.

I was imagining a scenario wherein the only available ammo for a 9 MM Luger pistol at hand during a fight is .380.
A ton better than nothing, though slow to load, and keyholing projectiles can still kill.

[ThomasT]

My bud had a coon on his back porch and in his haste to load his Glock 19 he loaded a few 380s instead of 9mm. He said it fired and cycled a couple of rounds but the animal escaped. Then he noticed that he had loaded the wrong ammo. No harm was done to the pistol. He separated out his ammo a little better. So yes in some guns the 380 may work. Sort of. I suspect the extractor held the 380 rounds enough for the gun to fire them.

[ferrarif1fan]

I know lots of people are saying it CAN be done, but I personally think you're flirting with disaster when you start messing around like this. Take your 9mm barrel out of your gun and drop a .380 cartridge into the chamber. You'll see immediately that it isn't even close to a match.

The cases on cartridges are not intended to contain the explosive power of their firing all by themselves. They are designed to be placed in a chamber that fits relatively tightly around the case before firing. If you start placing them in enlarged chambers, I think you're just asking for trouble. Better to just not do it than risk blowing up a pistol, or worse, damaging your hands, face or eyes.

[Jim Watson]

There was one agency issuing 9mm Berettas that would insert the occasional .380 in to promote malfunction clearing during training. The .380 would feed and fire, but not function the slide, leaving the trainee with a problem to sort out before he could proceed.