According to Federal factory ballistics, the .300 mag adds about 300 FPS to a 180 gr bullet. That equals about 150 yards.
With elk, on public land, I want them down fast.
On a broadside elk, eather calibur will do it, but will someone tell me where to find these elk that always stand broadside for you ?
Why take the chance on penatration issues ? If you can shoot the mag, shoot the mag, loaded with Partitions or the like.
