I had a Katahdin setup in 450 Marlin.I killed several deer and a few hogs with it.I got a wild hair up my ass and traded it away.I am haunted to this day about that decision.The 45-70 is a great old cartridge and should do the job on your mt lion quite nicely.Good luck,look foward to the story and pics.I just picked up a 15" 460 S&W that I am having a permanent brake affixed to to make it into a carbine.Should be a blast.
Jim
