[Sevens]

You can make an argument that:
--.45 Colt is an OLD cartridge and for it to compete in the horsepower race with the .44 Magnum, it needs to be hotrodded beyond the scope of it's original design (which it seems to do fairly well)

while...

--the .44 Magnum was designed from the ground-up to be a hardcore, power-spewing revolver round that leaves a big hole.

Using this argument, you might make a vote for the .44 Magnum sticking true to it's design envelope and then perhaps...it's a more natural "king."

But you can counter the argument with the .45 Colt's larger bore and thusly providing similar energy with LESS pressure, or MORE energy with the same pressure. But make no mistake, it's fact that for the .45 Colt to compete in any race where "power" is a concern... it must be run outside the scope of it's original design to compete with the .44 Magnum.