Today�s shooters regard the 7mm STW as the cutting edge of modern magnums, but it�s almost exactly the same round as the 7mm Mashburn Super Magnum that Field & Stream�s Warren Page used all over the world in the 1950s, and basically the same as the 7mm-300 Weatherby wildcat that�s seen use over the past couple of decades. All three are "full-length" belted magnums, derived from the circa-1912 .300 Holland & Holland case, so have almost identical powder capacities and ballistics.
Don�t get me wrong. Layne Simpson�s dream-child obviously provides velocities a notch above the 7mm Remington and Weatherby magnums, though it doesn�t outdo the Mashburn round, even back when Warren Page filled its case full of war-surplus H-4831. But Layne�s variation uses the 8mm Remington Magnum case, with no need to be fireformed like the .300 H&H brass Page used, and is much cheaper than the .300 Weatherby cases needed to make the 7mm-300. An STW fan just needed to run an 8mm case into an STW die and presto! Super Seven!
