Lot of "experts" here who have never hunted lion seems like...
I do not know
IvW, I have never hunted Lion...
But I draw my conclusions on the .338 caliber for Lion based on the vast number of well published genuine field experts such as Bell, Taylor, Anderson, Sutherland, Grogan, Longden, Lyell, etc. etc. who praised highly the .318 Westley Richard ... which is actually a .330 caliber.
I guess that if the .33 250 gr bullets at 2,400 ft./s of the .318 WR worked well for them with the bullets of the era, the .33 250 gr bullets at 2,600 ft./s of the .338 Win are likely to work very well indeed today with modern bullets such as the TSX, AFrame, Peregrine, etc.
An interesting advantage of analytical thinking is that it has allowed man to understand the criteria at play in given situations, conceptualize their applicability in experiences that they never had before personally, and project their application in experiences new to them. For example, I always found quite remarkable that the Apollo program was able to analyze, conceptualize and design hardware to take man to the moon, land him and walk him around, and return him safely to earth, executing flawlessly a program designed entirely based on analytical thinking and without, obviously, any prior moon exploration experience.
Of course, not everyone is a rocket scientist, or a ballistician, or a bullet designer, etc. but I reckon that members of AfricaHunting.com too are capable of analyzing and drawing valid conclusions