The 7mm/300 Weatherby Mag is a real good cartridge that has been around a long time.
They will kill deer and elk much further then 1000 yards.
The 8 twist and added speed in the 6.5/300 Weatherby (3350 fps) and 140 to 155 gr seem to kill a bit faster then the 7mm though.
The load I use in my 7/300 Weatherby is, 85 to 87 Grs of WC 872 (almost identical to H870), the 168 Gr Sierra Match King, Federal 215 primers. I have a 30" barrel on it also.
Speed is 3250FPS
Thats the information on the 7mm/300 Weatherby.
Darryl Cassel