Re: 270 win sierra gameking for elk?
I've used the 130 Sierra Boat Tail for years. Have taken many mule deer with it.
Learned that the longer the range the better. Loaded hot, 3190 fps, anything closer than 250 yards the damage was brutal. Much loss of meet. Sometimes the entire front half.
130 Ballistic tips shot exceedingly well. Have not taken any animals except yotes. Works really well. Tears 'em up.
I really prefer the Hornady HPSP in 140 grain for use in the 270 Win for deer and elk when I happen to be carrying that rifle.
If you have a typical chamber, use CCI 200 primers, RL-22 and seat the hornady with the back of the cannelure exactly at the mouth of the case as a starting point.