I appear to be missing the point of this I think.

As I read this the poster is a custom bullet maker who is effectivly advertising on the forum and testing his product by giving it to members of the forum to load using data extrapolated from a bullet 40 % lighter.

No pressure data, no test barrel, just primer cratering as an indication of pressure? No COL?
In fact there is no pressure data on his web site just the usual warning about using the data in any other rifle Etc.

I stand to be corrected, but that bullet appears to be too long to function in a standard length action without significantly impinging on powder space (which is marginal in 458WM anyway).

And to what purpose. There are many FMJ solids that will out perform that bullet at reasonable cost and proven not to bend or deflect in the most extreme of circumstances.
The accuracy is piss poor, a factory CZ with factory ammo, will put them in one hole at 50 yards and not beat the snot out of you. Recoil or rifiling twist...Hum. So one has either to build a custom rifle to fire this over bulleted cartridge, or it is so poorly balanced in terms of power V recoil that the average man cannot hold a group with it. All of the above to produce 10% less power than a .458 Lott in a standard length action.

A good quality soft point is better for N American game and for Africa a premium solid would be a much safer bet for DG in extremis.

This late obsession for proving that a solid lead slug will penetrate X inches of wet whatever is incomprehensible. On the site is a comparison photo between a lead solid and what appears to be a fully expanded Barnes X or failsafe. What is that suposed to prove other. than the Barnes or whatever has performed beautifully. It is apples and oranges.

Solid lead bullets are an anachronism form just after the turn of the century in modern cartridges. As soon as professional hunters could get better bullets they did.

If anybody else wants to risk their rifles or themselves testing projectiles, I have turned some .458 plastic sabots into which I have inserted solid tungsten carbide penetrators. Recon with 60 grains of Bullseye we can fire them through the side of an armoured car...any takers?