JCN has all kinds of bad ideas: 380ACP out of a J-frame

[JCN]

So as a preface, 9mm works well out of a <2” barrel.
Arguably better than 38 special and 357 magnum if you are talking about ballistics and shootability.

I wondered how 380ACP might fare out of something like a J-frame.
I know Taurus makes one...

So I bought some Taurus 380 moon clips to see if I could fit them in my Ruger LCR9.

The answer? Nope. The hole spacing is different between guns...

And there’s probably too much of a gap around the cartridge to be safe anyway.

But... but....

Stephanie B sometimes it’s not in the manual because nobody has thought of it or it’s a really dumb idea.

The Taurus moon clip fits perfectly on an uncut J-frame and the 38/357 chamber is actually a better fit for a 380ACP.

70521

That’s with the moon clip fitting.

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That’s with 380 snap caps in place.

Cylinder closes and rotates without binding...

70523

This MP340 has an Apex kit with the firing pin and it looks like it’s centered.

Anyone interested in a chrono, range report and video tomorrow?

Could this be an easy and cheap alternative for a light J-frame?

Am I dumb?

jetfire if it works it can be a GAT article...


http://www.YouTube.com/watch?v=p_rehbT9IrM

[Stephanie B]

I don’t know if it’s dumb or not. But I haven’t seen cheap .380s in a ling time.

[SiriusBlunder]

TL;DR: The consensus seems to be that due to head-spacing issues and other reasons, you probably won't get reliable ignition.

https://pistol-forum.com/showthread.php?41805-Firing-380-out-of-9mm-Revolver

[JCN]

I don’t know if it’s dumb or not. But I haven’t seen cheap .380s in a ling time.

I’m not worried about cost or availability, just shootabilty and ballistics.

I also wouldn’t be surprised if 380 recovery precedes 38/357 in a general sense.

I’m in good shape for 38/357/380 target and SD ammo for a long while so it’s just a feasibility experiment.

[JCN]

TL;DR: The consensus seems to be that due to head-spacing issues and other reasons, you probably won't get reliable ignition.

https://pistol-forum.com/showthread.php?41805-Firing-380-out-of-9mm-Revolver

That is correct... trying to shoot 380 out of a 9mm revolver.

This is shooting 380 out of a 38/357 revolver.

Headspacing looks perfect and firing pin strikes are dead on....

70524

[SiriusBlunder]

That is correct... trying to shoot 380 out of a 9mm revolver.

This is shooting 380 out of a 38/357 revolver.

Headspacing looks perfect and firing pin strikes are dead on....

70524

My bad, I read "LCR9" and my brain stopped processing.

Hope it works out. Interested to see your results.

[TheNewbie]

Very interested to see results.

[JCN]

DMWINCLE by putting 380 in an uncut 38/357 cylinder the moon clip basically holds the 380 case where a 357 rim would be.

38 special
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380 with moon
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[CCT125US]

Sort of hope this works.

Sold off all my .380s years ago, but still have ammo, and brass, so much brass, and bullets are cheap.

[Duelist]

Huh. That might be kind of cool.

[Totem Polar]

Not sure if I’m watching awesome, evil genius or a train wreck, but I can’t wait to see what happens next.
:D

It’ll probably work.

[TheNewbie]

This excites me more than the new HK pistol. I am serious.


Judge me as you see fit.

[MandoWookie]

"Your scientists were so preoccupied with whether they could, they didn't stop to think if they should."

This is a mad science project I can get behind. I'm curious if it works, would recoil be less than wadcutters? Accuracy and point of aim? Would it be similar to those Magtech .38 Special Shorts that are so fun to shoot?

[Doc_Glock]

Definitely interested in your results. This could be good for the recoil sensitive amongst us.

[Mitch]

No idea why, but I really want to see what happens here.

[JCN]

Not sure if I’m watching awesome, evil genius or a train wreck, but I can’t wait to see what happens next.
:D

It’ll probably work.

Awesome evil genius works. :D

I’m just a curious guy who likes to test hypotheses.


This excites me more than the new HK pistol. I am serious.

I’m pretty jazzed. I used to do a lot of ballistic type and shootabilty tests, but then I answered all my questions regarding carry.

Haven’t done a test like this in a while. It’s fun.


"Your scientists were so preoccupied with whether they could, they didn't stop to think if they should."

This is a mad science project I can get behind. I'm curious if it works, would recoil be less than wadcutters? Accuracy and point of aim? Would it be similar to those Magtech .38 Special Shorts that are so fun to shoot?


Definitely interested in your results. This could be good for the recoil sensitive amongst us.

The reason I thought of this is that short barrel ammo is deceiving. 9mm out of a short barrel revolver is ballistically the same as a lot of 357 magnum but WAY more shootable. At those barrel lengths the case length difference winds up mattering.

So what if we had a similar situation with 380 where it’s more shootable but similar ballistically to 38 special?

Feels are deceiving for ballistics so that’s why I like testing.

If it works I’ll do some 5 shot rapid fire drills for speed and group. With some video to show the recoil difference.

[03RN]

Being able to scrounge ammo is cool but I still think Id prefer .38s if I had a choice

For training or gaming its definitely sounds like a plan though

[jandbj]

I have gotten more joy out of JCN’s what if questions lately... keep rocking the road less traveled!

[FNFAN]

Next thing we know you'll be shooting 40 S&W out of your 10mm!:rolleyes:;)

[Trigger]

I wouldn’t. The .380 (9x18mm, 9mm Kurz) is a tapered case, the .38/.357 is a straight walled case. In your photo below, you see the chambers cut into the cylinder, with the front end of the cylinder cut to size smaller than the chamber, but large enough to lead to the forcing cone of the barrel. When you fire the .380 round, there is no way to hold the tapered case concentric with the bore of the cylinder, and the bullets will likely bang into the end of the cylinder and the forcing cone unpredictably, potentially causing pressure spikes. Plus you have the difference in case length, leading to fouling buildup in front of the 380 case mouth, which will make it difficult to shoot the longer .38/357 later due to the fouling buildup.

70521

That’s with the moon clip fitting.

[Duelist]

I wouldn’t. The .380 (9x18mm, 9mm Kurz) is a tapered case, the .38/.357 is a straight walled case. In your photo below, you see the chambers cut into the cylinder, with the front end of the cylinder cut to size smaller than the chamber, but large enough to lead to the forcing cone of the barrel. When you fire the .380 round, there is no way to hold the tapered case concentric with the bore of the cylinder, and the bullets will likely bang into the end of the cylinder and the forcing cone unpredictably, potentially causing pressure spikes. Plus you have the difference in case length, leading to fouling buildup in front of the 380 case mouth, which will make it difficult to shoot the longer .38/357 later due to the fouling buildup.

70521

That’s with the moon clip fitting.

I don’t know about the rest of it, and I’m waiting to see what happens, but you are mistaken about the .380 being a tapered case. 9x19 Parabellum is tapered with .394 case head and .380 case mouth, while the .380 is .374 case head, .373 case mouth. .38 Special has .379 as the spec for the case mouth, so there will be room for the .380 case to expand in the chamber. I rather imagine that it will. I doubt the slightly smaller bullet passing through the rest of the chamber after it leaves the case is going to damage anything, or we’d already see that after the last ~100 years of shooting .38 Specials through .357 chambers.

[JCN]

I wouldn’t. The .380 (9x18mm, 9mm Kurz)

That’s with the moon clip fitting.

Good points! But 9x17... 9x18 is Makarov which doesn’t fit because of the wider base of the cartridge.

Will be interesting to see where the accuracy shakes out at!

[Duelist]

Good points! But 9x17... 9x18 is Makarov which doesn’t fit because of the wider base of the cartridge.

Will be interesting to see where the accuracy shakes out at!

I think that the accuracy will not be terrible, because we have been shooting 9 mm Parabellum through .357 Ruger Blackhawk barrels in the convertibles for generations, and while the accuracy isn’t as good typically as the .357‘s or .38s, it isn’t usually terrible. .380 and 9mm Parabellum bullets are both nominally .355, so it should be comparable.

[Stephanie B]

It might work. It might be a “Hold my beer and all y’all watch this” exercise.

[JCN]

I think that the accuracy will not be terrible, because we have been shooting 9 mm Parabellum through .357 Ruger Blackhawk barrels in the convertibles for generations, and while the accuracy isn’t as good typically as the .357‘s or .38s, it isn’t usually terrible. .380 and 9mm Parabellum bullets are both nominally .355, so it should be comparable.

I think he’s concerned that due to the case mouth being not centered the bullet might hit the cone/barrel a little crooked or wobbly. I’m not sure how much wobble and slop will matter.

I definitely think 380 out of a 9mm chamber isn’t going to work because of the floating case but the 380 fits decently snug/centered I think.

We shall see! This thought experiment might only last one round, lol.

[03RN]

“Hold my beer and all y’all watch this”.

That's my middle name

[JCN]

Http://www.YouTube.com/watch?v=tLnv5A_lEOA

It worked and was super pleasant and mild to shoot!

But velocities and accuracy were meh, as people had suspected.

70554

Same ammo out of an LCP:

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7 yards semi slow fire with the J-frame: 380 versus 38 special

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So while you could do it and it’s very mild to shoot, it has limited SD application.

Trigger and 03RN win for the most accurate predictions!

[Trigger]

Glad it worked out safely, even if it was underwhelming.

Thanks to all for correcting my errors, I need to verify better before posting! I will say 380 is pain to deal with then it gets mixed into my 9mm cases.

[jandbj]

JCN has all the cool toys.

I’ve lusted after an LCP Custom since they stopped making them. Wish they’d put those sights on the LCP2 in .380 & .22LR! Time to hit up the Ruger suggestion box again.

[GearFondler]

Well this was a fun thread.

Load it with .380 FMJ and it would still do the job if it didn't ricochet off bones.

[jh9]

So while you could do it and it’s very mild to shoot, it has limited SD application.


FWIW, you can have your .357 cylinder machined to take .38 super and the rimmed special cases are, as advertised, usable without the moonclips. So the difference in neck and base diameter between the .38 super -> .38 special -> .380 ACP is about even at roughly ~0.006" each step. The difference between shooting a .38 special in a chamber machined to .38 super isn't much worse than shooting a .380 ACP in a factory .38/.357 chamber.

I wonder if the .38 super using .38 special has a similar drop off in velocity. I would assume so.

[mmc45414]

On a tangent, I understand people use 38 Short Colt in 38/357 to reduce the case capacity for mild loads.

And OMG, one of the first things I have looked up in months that was IN STOCK!!! :cool:
https://www.starlinebrass.com/38-short-colt-brass

[Velo Dog]

A Taurus 380 UL revolver pushed a 95-grain bullet to 887 fps from its 1.75-inch barrel.

That matches the velocity from the Ruger LCP. The 223 FPS difference seen in JCN's test is telling.

https://www.shootingtimes.com/editorial/taurus-380-revolver-review/365617

[randyho]

Trigger and 03RN win for the most accurate predictions!
And you have discovered a source for moderately accurate 38 sub loads! Thank you! Now you just need to suppress that jframe #SCIENCEANDSHIT (https://pistol-forum.com/usertag.php?do=list&action=hash&hash=SCIENCEANDSHIT) !

[Stephanie B]

On a tangent, I understand people use 38 Short Colt in 38/357 to reduce the case capacity for gamer loads.

FIFY.

[JCN]

Taurus Model 380 (https://www.1911addicts.com/threads/taurus-380-wheelgun.129158/)

No affiliation with the seller, etc,etc, just doing my bit to help.;)

Thank you! I bought it today for $375 shipped!

It took me this long to prove I wasn’t a spambot on the forum and by that time the price had dropped $50!

:D

[awp_101]

Thank you! I bought it today for $375 shipped!

It took me this long to prove I wasn’t a spambot on the forum and by that time the price had dropped $50!

:D

Congrats! Spending other peoples money is just one of my many hobbies...