The 139 gr. Hornady SP will work fine on deer at 2850 to 2900 fps out of the X-Bolt as will most of the 140 gr. bullets. However, for whitetails or mule deer, so will the 120 gr. Ballistic Tip or the 120 gr. TTSX. Having said all that, none will actually "knock down" a deer unless the central nervous system is hit. Even then, the deer won't be knocked down, it will just drop. I don't mean to rant, it's just that the term "knock down power" describes something that doesn't exist in a weapon that can be held in your hands. By the way, welcome to the Campfire.......oops! Just noticed that you've been here a long time, just haven't posted much. Oh well, welcome anyway.
Last edited by lastround; 10/20/14. Reason: Added a little
