Good luck on your lion hunt Tom! One things for sure, you're going to get 3 different answers. I used my S&W 8 3/8's 357 magnum & a Keith 173 gr. cast bullet on my lion. I was up in the tree with it & the shot was about 4-5 feet away. The lion hit the ground, took one giant leap & died in mid air.
You might be shooting from the ground & the lion might be 60 ft up a tall pine tree. The guide will tie up the hounds so one of them doesn't get killed by a wounded lion when it hits the ground.
Lots of options here, others will chime in & all will be good opinions.

Dick