Turning 9mm into 380?

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Prof Young

New member
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
 
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?
 
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
 
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.
 
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.
 
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
 
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.
 
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.
Click to expand...
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.
 
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