PRC burns a little more powder, the cartridge allows for longer projectiles without getting into powder column or having neck issues and due to those things I'm able to push a 220 grain pill at a similar speed to what the 300wm pushes a 200. A lot of that depends on particular powder/load but overall the 300prc is close to 100fps faster with the heavier bullets.Is there that much difference between the 300 WM and the PRC?