Who likes the idea? 9mm, 40S&W, 45ACP, 10mm,
With short rectangular magazines it would look a lot like an M1 Carbine.
Personally I envision a Mini 14 in 10mm. Get an ammo maker to work up some loads with slower burning powder to take full advantage of the longer barrel. Still compatible with pistol ammo...
180gr 40cal bullet at 1800fps sounds pretty good to me.
With short rectangular magazines it would look a lot like an M1 Carbine.
Personally I envision a Mini 14 in 10mm. Get an ammo maker to work up some loads with slower burning powder to take full advantage of the longer barrel. Still compatible with pistol ammo...
180gr 40cal bullet at 1800fps sounds pretty good to me.