Gentlemen- the question has been answered. Regarding Mercury Vacuum projectiles, and removing atmosphere from armored vehicles- please note you are about to seriously embarrass yourself. The poster from New York should know that NY State outlawed 50 caliber rifles in 2005.
You are both posting on a website frequented by professionals, including former and currently serving members of the military, along with a few weapons designers, manufacturers, and senior Dept of Defense personnel.
Question having been answered, thread is closed.