I have been playing with my .458 Winchester and found using 500 grain banded solids and 60 grains of Reloder 7, with Winchester brass, and a Winchester large rifle primer, I was getting an accurate 1970 fps. About 100 fps less than I had hoped for. 25 inch barrel. Any suggestions?

Barnes website has the info you'd like. Same bullet and just shy of 2200 fps with a 24 inch barrel. TAC is the propellant. Look under "Home, Technical,Load data, .458, 458 win. mag.
Order up the free DVD also, and watch some of the high speed X bullet movies. (cheap thrill..Wheee)