Since we are going over this again.
I have seen a "few" lions killed with guns, and a few with bows, the best advice given, is "shoot what you are comfortable with". .22mag works fine, as does any thing else. Had one lion shot over dogs with a 45/70, with a cast bullet. The lion stayed in the tree "leaking out", and hit the ground dead. Not my first choice, but it dam sure had the desired result.
Over my dogs, I want the lion dead in the tree, not "blown out". I don't chain dogs back.
Any good shot, with the right bullet(regardless of caliber) will be just fine.
With a bow, double lung the lion, and "PRAY FOR THE DOGS"
thats all I have to say.