With a 125-158 grain bullet it would shoot as flat as a bo and hit much harder. Ive been playing a lot lately with the BO. Its a cool little round but you have to be very selective in bullet choices for hunting deer sized game. this one would take care of business even with cast bullets. Yes a guy could say that so would a 450 bush 458 socom or 50 beo. I shoot the beo myself and love it but could see the use for something that was a little bit less for deer. I could see myself getting an 8.5 inch braced ar pistol chambered for it for whitetail hunting. Looks like its a straighten out 556 case but didn't really say what the case was based on and if you could make brass or would have to buy it. that's one thing I like about the BO. I can easily make brass out of about free 5.56 brass. Couple other advantages I can see is even if you didn't cast you could buy cheap bulk pistol bullets to plink with and it would really excel if you wanted to actually hunt subsonic as a 180-200 grain jacketed hp or soft nose pistol bullet at 1100 fps would be a much better subsonic deer killer then anything subsonic out of the bo. Heck you could probably even shoot 180 cast lfns at 1100 and kill deer just fine. If its based on a straightened out 5.56 case and fits in an ar15 sign me up.