Firing 380 Auto in a 9mm Luger?

[KentM]

I reload 9mm from range brass, and sometimes I find 380 Auto casings. So far I've always caught and eliminated them but I'm always afraid of one slipping through.

So what would happen if I accidentally loaded and fired a 380 (with a 9mm powder load) in my 9mm semi-automatic?

 

[Jake in TX]

Assuming the extractor holds the cartridge firmly, the cartridge will go off.

Jake in TX

 

[Englishmn]

Bullet would be high in case so volume should be similar. Probably wouldn't notice a difference.

 

[edwardware]

As @Jake in TX says, it'll fire if the extractor holds it. In my experience the bullet will exit the muzzle, but the slide will not cycle, and ejection is very unlikely. The case will be ballooned above the thick base, much like 9mm in a .40S&W.

You should try, so you know for yourself.

 

[Bosn Ski]

I took a class with a person who bought .380 ammo and tried to use it. The ammo shot fine, but there was cycling and ejection issues.

He took a lot of grief for that.

 

[doorman]

These pistol rounds head space off of the case mouth so you would be out of spec. Additionally, as mentioned above, if the extractor has a good grip it will go off, if not you would run into a light strike scenario or failure to fire at all since the case is to far in the chamber.

 

[mdi]

Yep, as mentioned above. But during reloading you should be able to see differences. I have had 380 brass get as far as sizing/depriming, and the difference is very noticeable; 380 brass just slips into the sizing die with little resistance from smaller case diameter. If you get as far as bullet seating the case length should be noticeably shorter visually (.740" shorter).

 

[1KPerDay]

Done it. Case blew up to the larger size but didn’t rupture.

 

[lordpaxman]

So what would happen if I accidentally loaded and fired a 380 (with a 9mm powder load) in my 9mm semi-automatic?

It somewhat depends on what you’re loading. In my case I tend to load very long for 9mm like 1.160 or so. If that’s in a .380 case, there’s very little neck tension and in my case it did headspace on the extractor and resulted in a squib. Sounded something like a dud firecracker. Fortunately the gun didn’t cycle. The net is it won’t result in a catastrophic gun failure unless you get a squib that you don’t clear.

 

[GEM]

Saw a guy who had a Browning BDM he bought cheaply. Brought it to a ranch in the TX Hill Country. Loaded a mag and jam, jam, jam. I said to let me look and he had bought a bag of 380 reloads.

 

[BC17A]

A 380 case probably wouldn't expand enough so you'd notice it as you tried to set a bullet, or if using a bullet feeder you'd more than likely crush the case mouth.

 

[JCSC]

I have ran a few thru the 9mm sizer and the handle just falls with no force.

pretty noticeable difference.

I would never fire one.

 

[dh1633pm]

I have found more than a few .380’s in with the 9’s. They have little to no resistance in the 9mm die. Easy to spot by feel of the press handle. Dump them in the recycle bin.

 

[Carl N. Brown]

9mm Luger cartridge,
9mm Luger casing fired in 9mm Luger chamber,
.380 ACP cartridge,
.380 ACP casing fired in 9mm Luger chamber.

.380 is a straight walled case.
9mm Luger is a tapered case.

I might be tempted to fire .380 ammo in a 9mm pistol in a survival situation but I would only count on it working as a singleshot.

I would not keep .380 ammo loaded with a 9mm charge. It would be a bit much if it got fired in a .380 pistol. I'm not sure I'd fire a .380 ammo with a 9mm charge in a 9mm pistol, looking at the bulge I got with .380 factory load in a 9mm pistol.

 

[GeoDudeFlorida]

I have found more than a few .380’s in with the 9’s. They have little to no resistance in the 9mm die. Easy to spot by feel of the press handle. Dump them in the recycle bin.

I’m probably the only one reading this who likes it when people give me .380’s mixed in with 9mm brass. My wife shoots way more .38Spl and .380 than anything else. .38Spl is easy to collect; .380’s vanish.
I wouldn’t worry too much about not being able to spot one in mixed 9mm brass. They actually kinda stand out.

 

[kerreckt]

I accidentally fired a .380 from my P228. It got loaded into a magazine of 9mm. Less noise and recoil. Other than that nothing. It ejected as it should. Really unremarkable.

 

[FROGO207]

I decap all my brass on a single stage press so when using my 9MM die a 380 feels no resistance when inserted in the die until the primer is pushed out. I don't even bother try to seperate them before decapping anymore.

Never fired a 380 in a 9MM yet so no help there.

 

[Dudedog]

Yes,
easy to feel .380 when decapping/resizing with a 9mm die.
As a side note .38 Super comp feel stiffer if they manage to sneak in....(and turn out bad if you try to flare them....)

 

[KentM]

(From the OP)
Thanks to all of you for your helpful responses. I feel confident now that at least it wouldn't be dangerous. And since I've now tried reloading 380s in my 9mm setup, I'm pretty sure I would notice one in among my 9mms.

 

[lordpaxman]

While I try to keep the .380’s out of the 9mm process, once in a while one slips through. I use a Shockbottle case gauge as a last QC check which holds 100 rounds and will definitely find them. It also helps insure rounds will chamber.

 

[LiveLife]

I reload 9mm from range brass, and sometimes I find 380 Auto casings. So far I've always caught and eliminated them but I'm always afraid of one slipping through.

So what would happen if I accidentally loaded and fired a 380 (with a 9mm powder load) in my 9mm semi-automatic?

Similar to shooting 40S&W in 10mm and 9mm in 40S&W ... Chambered round will "headspace" off extractor instead of case mouth and still go bang but not much as shorter case will leak gas around the bullet and case neck/base expand to larger chamber.

More fouling to clean up with reduction in accuracy along with slide cycling/spent case ejection issues.

 

[entropy]

Yep, as mentioned above. But during reloading you should be able to see differences. I have had 380 brass get as far as sizing/depriming, and the difference is very noticeable; 380 brass just slips into the sizing die with little resistance from smaller case diameter. If you get as far as bullet seating the case length should be noticeably shorter visually (.740" shorter).

.074" shorter, not 3/4" of an inch. Still very noticeable in the dies. I read the headstamp when I sort them.

 

[mdi]

.074" shorter, not 3/4" of an inch. Still very noticeable in the dies. I read the headstamp when I sort them.

Yep. As I said .074" No mention of .74 (besides, I always run a sub 1 inch measurement out to 3 digits, waaay more accurate. MDI didn't mention anything about 3/4"...

 

[Walkalong]

Yep, as mentioned above. But during reloading you should be able to see differences. I have had 380 brass get as far as sizing/depriming, and the difference is very noticeable; 380 brass just slips into the sizing die with little resistance from smaller case diameter. If you get as far as bullet seating the case length should be noticeably shorter visually (.740" shorter).

You had a typo.

 

[mdi]

Typo repaired? Thanks. I don't mind being quoted but I don't care for misquoting. My only reason for my reply. 76 year old hunt and peck typist left off a zero...