I have two elk with them, one at 845 and another at 910, around 2080 fps/1500 ft-lbs and 2130 fps/1580 ft-lbs at impact, and one big cow with a high lung shot dumped immediately and the other medium sized cow walked about 10 foot forward and dumped down from a heart shot. They seem to do well, though the one with the heart shot didn't exit. Got a total of like 14 or 15 big game critters with them this year. Last year I used the 147 eldm for 16ish big game critters pronghorn to elk, and switched to the 156. Next year, I will stick with the 156, if that says anything.