Owning guns in all 3 calibres (500 Nitro, 505 Gibbs and 500 Jeffrey) and having Shot Large Dangerous game
with a 500 x 3" Nitro, 505 Gibbs (525 grain and 600 grain bullets), I don't see a whole heap of difference.
They will ALL drop (and stop) a Buffalo if the shot is placed correctly.

One thing is for sure (and this comes from people who have used these guns on game more than me),
once you get over .5" in bullet diameter and 2150 fps, it is a big difference over a 470 Nitro et al.

I will however say that once you get a 500gn bullet at 2400 fps, it seems to be a step up but my question is,
does a 100 fps difference between 2200, 2300 and 2400 fps REALLY make that much difference on the animal
IF the shot is placed correctly. The OTHER factor people forget is the time it takes to get off the second shot
after recovering from the recoil - one reason I don't load any of my guns up to absolute Max.

I would welcome other poster's thoughts on the above comment.

Also, getting a 500 Jeffrey up to 2400 is not that easy - most of the 10 or so 500 Jeffries I've seen tend to end up
around 2300 fps with 535gn bullets.

500 Nitro