Howdy Mr. Tickle! Welcome to the forum.
Starline does offer brass in many calibers, but I don't think that they offer 30-40 Krag. I believe that Hornady uses PPU/Privi brass for their loaded ammo, but they don't offer brass otherwise. I've written to a couple different cartridge manufacturers and received a (quite curt, to be honest) response from one of them. I believe that someone else wrote to Privi... and they would be the most obvious choice since they already manufacture .303 British, which is just a couple hairs off of 30-40. I'm hoping that Remington is still going to offer it for sale, since there really IS a demand for it (I'm thinking that Midway just didn't want to carry it anymore because of the lack of high volume sales it was generating, and used the Remington excuse to drop the line).
Paul
P.S. I just checked Starline's website, and as far as I can tell, they only offer straight-walled cases. Starline is definitely not making 30-40 Krag!
You're right, they don't list it anymore?
Steve