From Sferrin - The 6000 mph record shot was a test of the SM-3 KKV against a target simulator. The sound of the impact is pretty impressive. I'm more interested in the motor though:
"The Super Roadrunner motor developed specifically for the Hypersonic Upgrade Program produced 228,000 pounds of thrust for 1.4 seconds and weighed only 1,100 pounds. The maximum acceleration of the sled was 157-g’s, or 157 times the force exerted by gravity. When the payload impacted the target, it had 363 mega joules of energy that's equal to a car impacting a brick wall at 2,020 miles per hour."
So the sled's peak acceleration was 50% higher than a Sprint missile.
So my next questions; What was the Hypersonic Upgrade Program and for the energetic material scientists out there. Does anyone know what the chemical composition of the propellant was/is? Sorry for all the questions but "material science" including energetics is one area that holds incredible promise for "military overmatch" capabilities. Simply stated if your armor is better and your weapons have a bigger BOOM you make warfare, for the other guy, pretty difficult.