Ping-Pong Carbide Mortars

I tried to shoot a ping-pong ball from my Kilgore firecracker mortar and it broke the ball. Then I had this idea to make a carbide mortar sized to shoot ping pong balls. The small one was the first try and it worked, but it could have used more punch. The larger one works well! It will send the ping-pong ball thirty feet or so into the air. It also incorporates an integral magazine like most Big-Bang cannons do. I made a sub-caliber adaptor using pvc pipe and o-rings and sleved the big mortar down to 1" and tried it with wood balls. These things really sail!
Both mortars were cast from aluminum using the Lost Foam method.