I think of two wildcats off this cartridge that would be great. The 6.8 RAR and 22 RAR.

First, with all the light high quality bullets for the 6.8 SPC (TSA, Accubonds) you could get great velocity and flatter trajectory for deer/hog sized game.

Second, the 22 RAR would be the predator cartridge supreme in the AR. While probably not as fast as a 22/250, it should be mush faster than the 223.

With the 6mm Dasher being a big thing in 1000 yard shooting, this would be a great basis for just a little more umph.