Well I'm bored today, and curious, so I did some digging. You're into well heeled territory here, but I'd give these guys a call and see what they come up with if you really want it. Either that or figure out the 9.3x74R conversion. For light hunting or target shooting, a .41 Mag bullet will likely suffice once you have the brass. https://hendershots.net/product/405-winchester-extreme-custom-ammo/