I agree with Red Leg. If the argument is "good compromise between killing power, usability and availability of rifles and components. Its is a perfect cartridge for hunting all species in Africa from elephant to plains game as small as duiker," I will say from experience (I own .375 H&H, 416 Rigby, .458 Lott) that the .458 Lott recoil exceeds what most shooters are comfortable shooting casually, day in, day out, on a mixed bag hunt.
A 9 lbs .375 H&H rifle launching a 300 gr bullet at 2,530 fps produces 37 ft/lbs or recoil at 16 fps. A 10 lbs .458 Lott launching at 500 gr bullet at 2,300 fps produces 70 ft/lbs or recoil at 21 fps. Recoil is a less (55 ft/lbs) with a 400 gr bullet - it is lighter but it flies faster, the two factors influence recoil in opposite ways - but both sectional density and ballistic coefficients drop significantly.
With twice the recoil of a .375 H&H, all but the most experienced shooters will be much better served by a .375 H&H than by a .458 Lott on a mixed bag hunt.
I agree with this and I shoot both. I backed off the hot Lotts for practice. Yes the .375 is much more flexible than any of the headline calibers in this thread, but that is not the point. The point is pick one of the .458's. I picked the Lott because of the .458WM backup plan. With this option available I think it's unadvisable to step away from it in any direction other than toward the .375 H&H or .470 NE. I'm a cautious guy that carries more ammunition than he'll need and is always looking for options.
I have no experience with the Lott outside of a Ruger No. 1. It's a slight difference between the two in a hot 300 grain .375 and a 500 grain Lott. They're both abrupt and exciting. I enjoy the Model 70 Safari Express much more for extended firing. How heavy are your rifles?
Greetings Mr. Rutledge. My apologies for the latent reply, cell/email prohibited during working hours, apx 72 a week, yikes! I just wanted to thank you for keeping me in mind for possible 577 loads. I actually purchased a few rounds, however, the firearm is still on the fence at this point.
Many Thanks, again. Regards, Dan.