Round ball in .380 acp

[Rio Grande]

I've been wanting to experiment with cast round ball mouse fart loads in .380.....say two grains of Bullseye or equivalent.
This will be fired from a Short Lane 5" rifled adapter out of my 20 gauge.
Anyone try such a thing? I'd think the ball coated with LLA and loaded without tools/dies (just pressed in) might work.

[LAGS]

I am not going to comment on how much or what powder to use, but yes you can make a round ball load with out reloading tools.
I played with stuff like that ( .32 ACP & .38 Spl ) when I was a teenager 50 years ago.
That was before I bought my first reloading set up.
Now, What are you going to use the reloads for ?
Out of a shotgun barrel, you can probably get Minute of Box Car accuracy, but they will fire.
But playing with this kind of thing taught me a lot ,like, This would be a Last Ditch Effort to have something that would Fire Safely.

[Charlie Horse]

I load round balls for my 44 magnum Contender. They make good plinking/small game loads. I take some along when deer hunting.
I deprime then prime a fired case. No sizing. I like a small charge of Unique. Then I press a lubed roundball down as far as it will go in the case. Hopefully right on top of the pinch of powder. The ball is lubed with Lee Liquid Alox.
I like the ball down on top of the powder. At 10 yards those 44 RB loads shoot cloverleafs out of my Contender.
I think you should try shooting RB loads in your 380 adapter.

Sometimes I will run the finished rounds up into the sizing die, stopping by feel. This, in effect creates a really strong crimp. I think it makes the light charge of Unique burn more better.