Good questions,and I dont have all the answers. However, barnes MZ or spitzer boattails are my favorite for elk. I am using a barnes spitfire boattail 285 grains and 3 50gr pyrodex pellets. All I know is it is good/accurate for long range elk. However, some say the powder is more consistent. I killed my last bull elk with two 50gr and one 30 gr pellets pushing a 245 spitfire boattail by barnes. The elk was down in 35 yds from shot. However is was a little under 100 yds. This year at the caldera I may have a 150 plus yd shot and like the little extra weight of the 285.