Another possibility is synthetic cases. A friend of mine's been working on such a project for a couple of years now, obviously through a large corporation, and has gotten them to work very well in cartridges up to and including the .300 Winchester Magnum. Of course, making them would probably be more involved than turning brass, but otherwise they might be very viable. I'll ask him about it.
Hmmmm? , again.
I refer the reader back to my Arte Johnson you tube post.
Thanks JB,
Geno
PS, something the "average Geno" could make up on a reasonably priced 3D printer?