Oscar,
I would rate the 458 Lott as a good 200 yard Cape Buffalo caliber..Properly handloaded with IMR-4320 it will propell a 500 gr. bullet at 2350 FPS or a tad more in a longer barrel..
I used one for awhile and after shooting several buffalo I loaded it down to 2150 to 2200 FPS, got very mild pressure, and it killed buffalo, elephant, Lion and about everything else very well indeed.
I suspect one could hit and kill a buffalo at up to 300 yards or so, if he was a mind to do so...The caliber is very capable...but I wouldn't do that myself..The furtherist I have shot a buffalo with the Lott was about 50 to 75 yards. The Lott is a very capable and excellent caliber for all the heavy dangerous animals of our world..
The longest shot I have ever made on a buffalo was at 225 yards with a .416 Remington, 385 gr. Northfork soft, the one and only instant kill on a buff that I have ever made with heart/lung shot. He just tipped over on his nose dead..The PH, A.J. van Heerden, called him the teapot bull, A.J. said, "Hey boy,he just tipped over on his nose like a tea pot."