.380 ACP in a 9mm pistol: UPDATE

[jamesinalaska]

Two months ago I posted a "what if" question about shooting the .380 ACP in a 9mm pistol. Well, sorting through my ammo closet I found a half box .380 ACP cartridges and thought I would find out about my "what if".

And since yesterday was fairly smoke free, (we have four seasons in Alaska: fall, winter, spring and FIRE) I took a couple of 9mm pistols to the range and tried them with the .380 ammo. They shot fine. But not one - in any pistol - had the energy to push the slide all the way back to strip the next cartridge off the magazine. Every .380 fired produced either a failure to extract or a failure to eject.

As for accuracy, the .380 ACP shot point of aim at my target (a paper plate at 7 yards).

Just thought you'd like to know.

 

[sequins]

What if you replaced your recoil spring with one designed for a .380 or other lower powered spring? Would that make it feed? I want a P226 in .380 just as a novelty. The guys at the range would drop their jaws when they saw me filling the magazines with .380

 

[jamesinalaska]

Good Point Sequins

You make an interesting point; another "what if".

 

[rcmodel]

The fact remains that the 9mm case is larger, longer, tapered, and has a larger rim.

Firing a .380 in a 9mm chamber will work, if the extractor hook holds it close enough to the breech face for the firing pin to hit it.

The .380 case is too short to headspace in the chamber as it should.
But it may fire.

But it is not recommended to do it.

 

[WestKentucky]

Lots of guns have been tooled to run .380 from 9mm designs. It basically takes a different barrel, extractor, spring, and magazine to do it properly. The barrel needs swapped because the case is basically unsupported in the chamber, the spring needs swapped to allow the slide travel achieved with a 9mm parabellum, the extractor needs swapped to reliably extract a smaller based cartridge, and the magazine needs swapped to prevent staggering forward to back causing the rounds or the magazine follower to tip. So can it be done, absolutely so. Is it easy to just chunk a .380 in and try it out, yes. Is it advisable, no. If your that dead-set on running .380 in a 9mm gun look up a manufacturer of a conversion kit.

 

[hso]

Check for any evidence of marks on the rim of the .380 cartridges to see if there was any engagement or not. You may be seeing the FTE/E has to do with rim size more than anything else and luck for the one's that extracted.

 

[TheBigFundamental]

My fiancé actually tested this by accident the other day. Our ammunition was sitting together on the bench and she mistakenly loaded some of her P238 ammo into my 92a1 and fired. The gun would fire but wouldn't cycle and that is what tipped us off that something was wrong, 'cause that thing always cycles. Once the slide was locked back it was easy to see that something didn't look right about how the rounds were fitting in the mag.

 

[jamesinalaska]

THR members are making good observations. I wish now I would have been a little more thorough in my experiment so I could share better information. I can add this: only the first round did I drop the cartridge into a chamber to see if it would fit, all the remaining were pushed into battery from the slide stripping the .380 of its magazine. Even my cheapest 9mm would push the .380 cartridge into battery without a failure to feed. All the pistols except the glock 19 would extract the fired case to a point, but out of the half box of ammo I didn't have a single true ejection. The glock 19 more than any other pitol was the least likely to extract. But operating the slide manually extracted the case so I'm pretty sure the extraction claw was grabbing the case rim. I think, on the glock 19 anyway, the .380 was actuating the slide but only to a point where the slide then pushed the empty case back into the chamber.

 

[rcmodel]

The extractor Had to be holding the case rim or a Glock could not have fired them.

Without the extractor holding them back against the breech face, they would fall in the chamber too deep for the firing pin to hit them.

The .380 ACP case is .680" long to the headspace shoulder.
The 9mm case is .754" long.

So, the .380 is too short to headspace properly and fire, if the extractor hook isn't holding back out of the chamber.

rc

 

[hammerklavier]

Isn't the 380 also a tapered round?

 

[Delmar]

Head spacing on the extractor? I pass on that, but good to know its feasible I guess.

 

[Thermactor]

next i want to see a makarov round fired in the 9mm chamber

 

[rcmodel]

Isn't the 380 also a tapered round?

No, it's a straight case.

The 9mm is a tapered case.

rc

 

[230RN]

I remember seeing your thread here, or one like it on another board. It happens that at the time, I had collected my 9mm brass from the clean floor of the range and when I got home I found a .380 case in with the batch. I was firing with my right side against the wall, and the range was deserted, so it probably wasn't from another shooter. In looking back I "seemed to recall" a squib-ish load, but the gun continued to fire normally and my group was the usual minute-of-lousy. (Kahr CW-9, which is pretty light in its action.)

I was shooting reloads from Ten-X*, which is a pretty good remanufacturing outfit, and I wondered if a .380 had got into one of their boxes or a .380 case maybe got mixed in with the lot of 9's they were loading. I checked the remainder of the box and there were no more .380s in it.

I kept meaning to test out firing .380s in a 9 at the range, but never got around to it, so I really appreciate OP's and other input here.

Terry, 230RN

* I don't want to blame Ten-X, their reloads have been excellent, but the two cartridges can easily be mistaken for each other with a casual glance. and it's not impossible that I was the one who put the .380 in with the nines.

 

[jeepnik]

Gee, ever wonder why manufacturers put caliber markings on firearms? Oh wait they do it so folks will use the correct ammunition. But, the manufacturers can't control the highly suspect stuff people will do.

 

[Jim Watson]

I read of one government agency that would slip an occasional .380 in during training with Beretta 9mms so as to get their people used to dealing with malfunctions. The smaller round would nearly always feed and fire but not function.

On the other hand George C. Nonte once tested some of the 9mm Spanish Largo pistols sold here as "any 9mm or .38 auto." They would work with 9mm P if everything went right but a round in ahead of the extractor and a long protrusion firing pin are not a good combination.

 

[gulogulo1970]

I know wrong sub-forum but wouldn't it work in something like a 9mm revolver where the clip holds the rim of the case? Or are there problems I'm not thinking about?

 

[rcmodel]

They are two entirely different cases.

.380 ACP case = Straight case wall .680" long, with a .374" case head.

9mm case = Tapered case wall, .754" long, with a .394" case head.

The .380 case will bulge considerably when fired in a 9mm chamber, and may split.

rc

 

[wally]

next i want to see a makarov round fired in the 9mm chamber

9x18 won't fit in a 9mm (9x19) chamber, its too fat. The neck diameter is 0.392" compared to 9mm 0.380"

 

[Jim K]

The main problem is not the bullet diameter (they are the same) or the cartridge size, but the fact that most 9x19 pistols are of locked breech design, mainly recoil operated, and the .380 does not have the bullet mass and velocity to operate a recoil operated pistol designed for a larger caliber.

"9x18 won't fit in a 9mm (9x19) chamber, its too fat."

True, the 9x18 Makarov is too big, but the topic involves the 9x17, the .380 ACP.

"Lots of guns have been tooled to run .380 from 9mm (9x19?) designs."

Off hand, I can't think of any. "Design" in general, maybe, like the Llama .380 that copies the M1911, but the Spanish gun is a lot smaller and lighter. The same would be true of the .380 "Lugers"; small guns, lighter and smaller breechblocks. Same general design, but not at all the same gun.

Jim

 

[R.W.Dale]

I know wrong sub-forum but wouldn't it work in something like a 9mm revolver where the clip holds the rim of the case? Or are there problems I'm not thinking about?

Still a bad idea

This pic shows a fired 380 case lying in the cylinder of a 9mm revolver to illustrate why.

 

[JRH6856]

"Lots of guns have been tooled to run .380 from 9mm (9x19?) designs."

Off hand, I can't think of any. "Design" in general, maybe, like the Llama .380 that copies the M1911, but the Spanish gun is a lot smaller and lighter. The same would be true of the .380 "Lugers"; small guns, lighter and smaller breechblocks. Same general design, but not at all the same gun.

Ruger LC9 and LC380 come to mind...

 

[ahil925]

Being serious here,
Try this in a Hi-Point C9. The similarities between the C9 and the CF380 are great enough that some people have speculated that the *only* mechanical differences between the two are the recoil spring and the chamber cut.

If people have managed to get the .40 S&W Hi-Point to fire 10mm ammo just by reaming the chamber I'd be interested to see what a C9 would do if fed .380 ACP

 

[RainDodger]

Bad idea all around and I don't care what anyone says. A 9mm is a 9mm and a .380 is a .380. Put the cartridge in the gun it was designed for.

 

[FM12]

ist
Listen to RCModel. He's spot on!!