As much as I like Elmer Keith, you're right, he has nothing to do with this thread.
That I recall, the only bullet he ever really wrote about in the .45 Colt was the 454424, which, even in it's correct iteration, is far from the best choice (sorta stubby, give the bore size) today. We are currently blessed with better, heavier designs. I've read that Keith originally wanted the 454424 heavier, but Lyman (or Ideal or whoever was building those molds at the time) gave him a weight limit. So, that was what he designed, and what he wrote about.
Keith also either didn't have, or didn't fool with Win 296 (or H110, same stuff). I like 2400 for heavy-ish stuff in the old Colt, but for loading a Ruger Blackhawk to top end with heavies, it can't hang with 296.
Though my opinions are likely moot here as well. I have never killed an elk with a pistol, and likely never will.
That said, if I had to do it with a pistol, I'd hunt the devil on his own ground with a hard 270SAA and 25 grains of 296............
