Contact Barnes X Bullets and ask them about Dr. Ed AShby's experiences with the smaller 22 hornet afield in Africa. Lets just say he has taken over 600 big game animals, and some are much larger than elk. 
Personally I have used a X Bullet in a 222 to harvest a mule deer buck. One shot, one kill. On realtree outdoors Dave Blanton's son killed a nice whitetail with a 223. Deer sized game seems to be very doable if you do your part,
Chad
