This vacuum pressure cannon is a design unlike any we’ve seen before. At first look it seems to have the components you see in a potato gun. But those use a combustion process to launch the projectile. This instead uses the sudden release of a vacuum.
About three minutes into the demo video below we get a look at the “ignition” system. It’s pretty scary in that a couple of really powerful springs are pulling a collar along the barrel toward your face. This is actually meant to dislodge the plug in the back which is holding vacuum in the barrel. The pressure difference causes a sudden inrush of air which shoots the 1.5 inch projectile out the front of the bazooka.
[Mr. Teslonian] built his own hand powered vacuum pump for loading the weapon. This was done with a pair of PVC pipes that fit inside of one another, and a plunger made from wood and leather. The PVC and wood projectile seals in the barrel using a skirt made from duct tape. After breech loading the projectile and plugging the back of the barrel, he layers aluminum foil over the business end and pumps up a high vacuum. His test firing is not from the shoulder, and he only gets one shot because the slug hit the target so hard it was destroyed. This thing really needs to be vehicle mounted!