Turning 9mm into 380?

Prof Young · January 26, 2021, 09:50 PM

Well, I thought I was going to be making a query about how to turn 9mm brass into 380 brass. But then after hitting half a dozen websites for reloading supplies I found Everglades Ammo and they have range brass, in stock, in 380, for what seems to be a reasonable price. Then I decided to ask the question anyway.

Anyone ever turned 9mm brass into 380? Any easy ways to do so?

Life is good.
Prof Young

cdoc42 · January 26, 2021, 10:00 PM

Why?
A 9mm case requires a #16 RCBS shellholder while the .380 needs a #10. If you trim the 9mm down you will invariably risk a potential overload with a "new".380 case while you are actually loading 9mm rounds.

If you leave the 9mm case as is, all you might accomplish is loading down a 9mm to make it a short with more air space between the bullet and powder which has its own issues. Why not just settle for the .380 cases?

hounddawg · January 26, 2021, 10:03 PM

You can look it up on SAAMI, pretty sure case heads are a different diameter

nhyrum · January 26, 2021, 10:05 PM

The case heads are different. 380 is NOT 9mm short(kurz)

Sent from my SM-G975U using Tapatalk

JT-AR-MG42 · January 26, 2021, 10:42 PM

If I felt the need: (which I do not !)
You would first turn down the rim to .380 spec in your lathe,
then run the case through a swage die to reduce the diameter,
and then trim to length.
Last step would be back in the lathe to re-cut a proper extraction groove.

A simple water test would give you an idea of the reduced capacity of these new cases and so you'd
want to reduce charges for load testing.

JT

Shadow9mm · January 26, 2021, 10:50 PM

try no bull tactical. Its a little shop, you gotta call to order. 1000 380 for 46.99 + flat rate shipping. Ordered from them twice. Good brass if a bit dirty.
https://www.nobulltactical.com/produ...cessed-brass-1

rc · January 26, 2021, 10:53 PM

Different head means the thought it dead. Only similarity is really bullet diameter. You certainly can flip flop 115s and 90s in the two cases but neither is best with both.

**44 AMP** · January 26, 2021, 11:16 PM

just by the case drawing & specs in my Hornady book, it won't be a simple or easy conversion. 9mm is the size of the base of a .380 case at the mouth (ok, 0.001" smaller by spec) and TAPERS back to a base that is over 0.02" larger in diameter than the .380 rim.

As mentioned, you'd have to lathe turn each case, and do other things, as well.

Its called 9mm Kurz because it is 9mm caliber and its shorter than the 9mm Parabellum. Its not just the Parabellum case shortened, and it never was. The .380 case is smaller in diameter than the Parabellum, and essentially straight, as well as being shorter. These are not insignificant differences.

Prof Young · January 26, 2021, 11:30 PM

So the answer is no, not a good idea.
I didn't realize the heads were different.
Thanks to all.
So much to learn about all this gun stuff.
Life is good.
Prof Young

**Aguila Blanca** · January 27, 2021, 12:24 AM

Definitely not a good idea, and maybe not even possible. For future reference, bookmark this link:
https://saami.org/technical-informat...mber-drawings/

That page will take you to official SAAMI dimensional drawing for cases and chambers. A quick look will show you that, although they both shoot the same diameter bullets, the 9mm is larger in case diameter, and also has a taper where the .380 ACP is straight walled.

74A95 · January 27, 2021, 12:46 AM

Quote:

Originally Posted by nhyrum

380 is NOT 9mm short(kurz)

Sure it is.
https://en.wikipedia.org/wiki/.380_ACP
Other names for .380 ACP include .380 Auto, 9×17mm, 9mm Browning, 9mm Corto, 9mm Kurz, 9mm Short, and 9mm Browning Court (which is the C.I.P. designation).

**44 AMP** · January 27, 2021, 03:10 PM

I have a stack of reloading manuals covering decades, many of them have case drawings and dimensions. While not as detailed as SAAMI drawings, all the major information is there and I find them to be a useful quick reference.

As do the current manuals. Even if you don't reload, they're a handy reference. And the old books can be found cheap (if we ever have gunshows again...

)

Another good reference is Frank Barnes's CARTRIDGES OF THE WORLD. It does contain some errors and the author's comments on cartridges are his opinion, and more than a bit "dated" today, its still a fair reference.

Scorch · January 29, 2021, 05:38 PM

Quote:

Another good reference is Frank Barnes's CARTRIDGES OF THE WORLD. It does contain some errors and the author's comments on cartridges are his opinion, and more than a bit "dated" today, its still a fair reference.

A bit dated? That's an understatement! I was in the USMC with Frank Barnes' grandson (also named Frank Barnes, BTW), we went out to meet the old geezer, got an earful about my cartridge choices (30-30, 7X57 and 45 ACP). COW was in its 3rd printing then (1981), and it was a compilation of his opinions, good or bad. I've owned a 6th edition for about 20 years now, it looks like the 16th is the current edition. There is still a lot of his original work in the newest version, but various editors over the years have toned down his curmudgeonly comments. It's still one of the best cartridge reference books ever compiled.

January 26, 2021, 10:03 PM	#3
hounddawg Senior Member Join Date: March 1, 2009 Posts: 4,232	You can look it up on SAAMI, pretty sure case heads are a different diameter __________________ “How do I get to the next level?” Well, you get to the next level by being the first one on the range and the last one to leave.” – Jerry Miculek

January 26, 2021, 10:42 PM	#5
JT-AR-MG42 Senior Member Join Date: December 27, 2008 Posts: 555	If I felt the need: (which I do not !) You would first turn down the rim to .380 spec in your lathe, then run the case through a swage die to reduce the diameter, and then trim to length. Last step would be back in the lathe to re-cut a proper extraction groove. A simple water test would give you an idea of the reduced capacity of these new cases and so you'd want to reduce charges for load testing. JT __________________ I hunt not to kill, but rather to have not played golf...

January 26, 2021, 10:50 PM	#6
Shadow9mm Senior Member Join Date: March 21, 2012 Location: Indianapolis, IN Posts: 3,969	try no bull tactical. Its a little shop, you gotta call to order. 1000 380 for 46.99 + flat rate shipping. Ordered from them twice. Good brass if a bit dirty. https://www.nobulltactical.com/produ...cessed-brass-1 __________________ I don't believe in "range fodder" that is why I reload.

January 26, 2021, 11:16 PM	#8
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 28,820	just by the case drawing & specs in my Hornady book, it won't be a simple or easy conversion. 9mm is the size of the base of a .380 case at the mouth (ok, 0.001" smaller by spec) and TAPERS back to a base that is over 0.02" larger in diameter than the .380 rim. As mentioned, you'd have to lathe turn each case, and do other things, as well. Its called 9mm Kurz because it is 9mm caliber and its shorter than the 9mm Parabellum. Its not just the Parabellum case shortened, and it never was. The .380 case is smaller in diameter than the Parabellum, and essentially straight, as well as being shorter. These are not insignificant differences. __________________ All else being equal (and it almost never is) bigger bullets tend to work better.

January 26, 2021, 11:30 PM	#9
Prof Young Senior Member Join Date: August 21, 2007 Location: Illinois - down state Posts: 2,404	So the answer is . . . So the answer is no, not a good idea. I didn't realize the heads were different. Thanks to all. So much to learn about all this gun stuff. Life is good. Prof Young

January 26, 2021, 09:50 PM	#1
Prof Young Senior Member Join Date: August 21, 2007 Location: Illinois - down state Posts: 2,404	Turning 9mm into 380? Well, I thought I was going to be making a query about how to turn 9mm brass into 380 brass. But then after hitting half a dozen websites for reloading supplies I found Everglades Ammo and they have range brass, in stock, in 380, for what seems to be a reasonable price. Then I decided to ask the question anyway. Anyone ever turned 9mm brass into 380? Any easy ways to do so? Life is good. Prof Young

January 26, 2021, 10:00 PM	#2
cdoc42 Senior Member Join Date: March 13, 2005 Location: Pennsylvania Posts: 1,687	Why? A 9mm case requires a #16 RCBS shellholder while the .380 needs a #10. If you trim the 9mm down you will invariably risk a potential overload with a "new".380 case while you are actually loading 9mm rounds. If you leave the 9mm case as is, all you might accomplish is loading down a 9mm to make it a short with more air space between the bullet and powder which has its own issues. Why not just settle for the .380 cases?

January 26, 2021, 10:05 PM	#4
nhyrum Senior Member Join Date: March 9, 2016 Posts: 588	The case heads are different. 380 is NOT 9mm short(kurz) Sent from my SM-G975U using Tapatalk

January 26, 2021, 10:53 PM	#7
rc Senior Member Join Date: April 28, 2001 Location: CA Posts: 1,765	Different head means the thought it dead. Only similarity is really bullet diameter. You certainly can flip flop 115s and 90s in the two cases but neither is best with both.

January 27, 2021, 12:24 AM	#10
Aguila Blanca Staff Join Date: September 25, 2008 Location: CONUS Posts: 18,460	Definitely not a good idea, and maybe not even possible. For future reference, bookmark this link: https://saami.org/technical-informat...mber-drawings/ That page will take you to official SAAMI dimensional drawing for cases and chambers. A quick look will show you that, although they both shoot the same diameter bullets, the 9mm is larger in case diameter, and also has a taper where the .380 ACP is straight walled. __________________ NRA Life Member / Certified Instructor NRA Chief RSO / CMP RSO 1911 Certified Armorer Jeepaholic

January 27, 2021, 03:10 PM	#12
44 AMP Staff Join Date: March 11, 2006 Location: Upper US Posts: 28,820	I have a stack of reloading manuals covering decades, many of them have case drawings and dimensions. While not as detailed as SAAMI drawings, all the major information is there and I find them to be a useful quick reference. As do the current manuals. Even if you don't reload, they're a handy reference. And the old books can be found cheap (if we ever have gunshows again...) Another good reference is Frank Barnes's CARTRIDGES OF THE WORLD. It does contain some errors and the author's comments on cartridges are his opinion, and more than a bit "dated" today, its still a fair reference. __________________ All else being equal (and it almost never is) bigger bullets tend to work better.