So I have a father & son lion combo hunt coming up in mid April with Warthog safaris. I'm aware that high velocity calibers (read FPS) do better on felines with their "relative sensitive nervous systems" & I also read an article of a Lioness requiring 4 shots from a 500NE to go down recently , that got me thinking about my intended use of the 470 with its relative low 2150FPS, factory Barnes Vor-TX 500grns. Be that as it may, I have recovered some of the Barnes from the sand backstop I use at home as a firing range & they all seem to have expanded perfectly, even though I understand it is not the perfect simulation, it is much better than the DGX Hornady's that has separated completely & has given shallow penetration in comparison. My father plan on using his 458WM loaded with 500grn peregrine VRG3's ,not sure of the FPS but it is definitely not a FPS monster either. The scoped rifle carried by my father will act as back-up swop rifle should I have to take shots at longer ranges, say anything over 50M & the need arise where visibility is limited. He is looking at the VRG3 380grns instead to gain some FPS, and will be doing some load development over the weekend, though I'm not 100% convinced it is the best option either to go lighter. We have the alternatives, 9.3x62, 450/400 & .404 Jeff. but is not really what we have in mind, since we plan a second round but an all female personal big 5 of Ele, hippo on land, Lion, Buffalo & giraffe with the .400 rifles at a later stage. We are both competent with placing the bullet in the right place with either of these rifles which is most crucial. Are we over analyzing this or would you rather suggest alternatives? we will appreciate any suggestions & input.