With the 270WSM you basically get 250+/- fps additional muzzle velocity over the standard 270 win in a short action rifle with very little increase in recoil. The theory with the short & fat case is to expose a larger cross section of more slower burning powder to the fire which gives a more efficient burn and higher velocities. It is inherently a very accurate round (mine was) and the short action provides a lighter rifle with the short and stiffer action for better accuracy.