I dont buy into the live animal thing or field conditions thing. You are either practiced/capable of the shot or you are not. Heartbeats don't direct bullets.....
I get it. We don't need to take anything into consideration on 500 yard shots at unwounded BG animals.They are as mundane and routine as 200 yard shots I suppose.
IMHO it's not so much what you're shooting at (animal vs steel) (although a big buck or bull would make a difference) but more about the time you have to prepare and the stability of your shooting position. With steel, you have plenty of time and normally a good platform to get situated just how you want.
Not so much with improvised field positions on the side of a mountain or on a cactus-filled prairie with an animal that's not interested in staying put.
