Before the cartridges, Creedmoor was a shooting style or position used with handguns. The shooter would lie back, raise up the knee on his shooting side with the foot still on the ground, and rest the handgun against the side of his lower leg.
Be sure not to do this with a revolver! The 36,000 psi gas that comes from the cylinder gap on a 44 Mag will slice your jeans and leg open like a scalpel.
