Barnes makes the 110 gr TAC-TX specifically for the 300 BO application. I've read on other forums these bullets will tear apart in higher velocity cartridges so it may be just the right picking for the BO.

My hunting buddy got a chance to test his 300 BO AR pistol on a blacktail fork a few years back. Shot it at around 45 yards and it toppled over dead within 50 yards.

http://www.youtube.com/watch?v=GhB6Xh-uJDg