The 6.5x55 offers short action performance in a long action. It was a remarkably innovative cartridge when it came out (superior to the .30-03/06 almost a decade earlier) but suffers from all the problems of cartridges designed for machine gun use, plus being designed for an awkward intermediate action.
Just get the Creedmoor and have the superior gun.
Never heard of it being designed for machinegun use.
