To make it in the wild west you needed a fast draw which means quick arms which requires tendon strength and highly responsive muscles. Enter the Wild West workout. If you were a pistolero this is the workout you'd be doing to make sure you stay in top form. As it is, it's pretty cool in helping develop limb speed that gives you structurally faster punches, plus the additional focus on core and fascial fitness can't hurt either.
Extra Credit: 1 minute rest between sets.