Loading 380 using 9mm dies

[manny]

Did a quick video detailing how it can be done. You don't need to spend any more on another set of dies. This is why I love this sport.

https://www.youtube.com/watch?v=tP8G41ZgYtw

[Michael in California]

I did find you can do this accidentally. Darned stubby looking 9mm. Fortunately, it didn't fire.

[manny]

You got lucky. Shooting with some buddies last year I found the 40 cal I was using suddenly stopped cycling. Turns out a 9mm made its way in there and had expanded pretty violently. Got luck as it just stopped the gun and nothing more. Looked cool though.

[3RDGEARGRNDRR]

I would recommend a proper 380 resizing die as the 9mm has a taper but everything else pretty much works.
If your chambers are a bit loose more power to ya

[Pauliedad]

A friend shot a .40 round in my .45 once. Tumbled out and almost made it to the 15 yard targets, expanded the brass pretty spectacularly and taught me to watch my rook friends a lot closer.