Gentelmen,let's look at the other side of this coin!

I'm not saying you have not killed GODZILLA with a 600 gr bullet in a 458 Win Mag, but you could have done it better with a 450, to 480 gr bullet, IMO! All the 600 does is reduce the already slow speed of the 458 Win Mag, and increase recoil.

The big draw back to the 458 Win Mag is, it doesn't have enough powder capacity to handle even the 500 gr bullet properly, it certainly doesn't have enough room to do a real job with a 600 gr bullet! The 600 gr .458 dia bullet, made by Barnes, was designed for the 460 Wby Mag, not the 458 WM.

IMO, the 600 gr bullet would work fine in a 458 LOTT,though not needed. The Lott, which is what the 458 win mag should have been in the first place. Anything over a 480 gr, bullet, in a 458 Win Mag, will not get 2150 fps, and simply wastes powder, IMO! The .458 dia bullet works best @ 2150 fps. Tests have shown that when the speed is increased has a detramental effect on bullet performance, and below 2000 fps, retards pennitration, and tends to cause bullets to tumble, and go off course! The window is very narrow, for best results, in this diameter! Between 2000 fps, and 2350 fps, seems to be the best spread! The 500 gr bullet user is lucky to get over the window sill, at all, and I doubt the 600 gr bullet will get even close, in a 458 Win Mag case! Heavy recoil does not mean better killing power, it only feels like it does!

I have three 458 Win Mag rifles, one is a new, unfired, Ruger No1 Tropicle, that is scheduled for a 450NE 3 1/4" chamber! A pre 64 Mod 70, and a FN Mauser. Those rifles have not needed heavier bullets, but lighter ones, to get even close to advertized velocities!