Why? What would the 7mm Mashburn Super Magnum do that an available 7mm magnum cartridge wouldn't? When looking at the ballistic tables all of the short 7mm magnums and the Remington and Weatherby 7mm magnums duplicate or better it. Other than the slightly longer neck, a dubious benefit, is it worth the hassle? Mashburn formed it out of .300 H&H brass (except the Long version which used full length brass). It would require similar tooling to my .375 Epstein Magnum formed on the .375 H&H, form and trim die, ream die, full length die. Necks should be annealed due to moving so much brass and forming the neck from the parent brass shoulder. I'm sure that forming the cases out of .300 Winchester brass would require similar tooling if the new neck will be moved into the old shoulder.
Now a days I could just buy a .375 Ruger and open a box of ammo or brass.
Is it worth the effort?
