Sir Ron: When I began hand loading the .458WM, the bullet choices were limited, and dealing with the short case length, I had to prioritize case capacity vs velocity. Based on the information and components which were available at the time I decided to load to the same velocity as the forty-five caliber NE cartridges. Basically, 2150fps with a 500gr FMJ from a 24" barrel.
My rifle was/is a 1994 Winchester CRF M-70. Brass, Winchester. Primers Federal 215. Powders: AA2230, H-335, IMR 4320, H-4895, IMR 3031. Thirty odd years ago, if I had had the in depth information you've provided, I could have saved myself a lot of grief.
However, all things considered, I successfully accomplished my goal and actually exceeded all my expectations. Most of the bullets used in load development were 500gr FMJ Hornady. Early on, I was shooting Jack Carter's original TBSH bullets. Then I switched to Speer AGS. My PAC load was minimum 2100fps @ 30yds. Twenty-two hundred fps was readily attained with no pressure signs, but I found that 2185fps was the optimum in my rifle.
As an aside, the following are some factory 500gr FMJ ammunition. Velocities across the screens and corrected to muzzle. Five shots each.
Through the years I've listened to the experts bad-mouth the .458WM and attempt to convince everyone (who'll listen) the Lott is SO much better. I long ago dismissed their collective ignorance and moved on. To each their own.
