I am going to put one together for my 510HE, my little
rimmed wildcat case, using a #1. Will have big long barrel, weighted stock, big pad, and the 11-12000 ft lbs shouldn't hurt.Ed.

It will be built for one or some of the Elephants that are to many of in Zim..

Already have a .404 and wants something more than the .458 class for the tricky situations...

It shall not be a wildcat, so i am rather limited to .500 Jeffery, .505 Gibbs or .500 N.E...

Maybe the best option actually are a .500 Jeffery?????

Yes,

They have been chambered to 577NE, and SSK also has a wildcat using the 577NE cas blown out to take the 600 NE bullets.

It has been said the Ruger can't take full pressure loads in 577 NE. It has also been said that the largest practicle round for the #1 is the 500 NE, but with the 550 magnum coming out, it might now fill that niche.