I don't buy "dumping energy" view of lethality. It is about major organ damage and blood loss. The two dozen or so animals shot by my son and I with copper have all failed to make it more than 20 feet from where they stood. From deer to pronghorn to kudu to elk to black bear to zebra, etc. 100% first shot drop dead kills. The entire lung cavities look like they have been put through a blender, shoulders totally shattered, etc. Most punched through both sides so only have recovered two of them, but looked just like the manufacturers "petal" pictures.
I have 100% confidence in monos made by Hammer and Barnes.
As for velocities, we use manufacturers specs (typically 2000fps or 1800fps) verified with actual range dope to set the max distant shot we will take with given cartridge. For the most part we won't take shots at big game beyond about 425yds - even though some of our rounds have the capability to be effective further and we shoot regularly at range beyond that, we just don't feel right pushing it when it comes to living creatures under field conditions. For us it is hunting, not shooting live targets. To each their own, but we prefer not to push everything to the edge of performance - we try to reduce variables to ensure ethical kills.