You could build your own...
We had one in my 20's that was made of a service station hydraulic lift ram cylinder (chrome bore), about 5' long, blanked off on one end with a touch hole and mounted on some 24" steel wheels. All built by some Aggies that had moved down here. The bore was perfect for a steel beer can filled with cement. IIRC we used 1/2 of a beer can of black powder. (Our measuring device and projectiles both came from the ice house--- kept things simple)
We had one in my 20's that was made of a service station hydraulic lift ram cylinder (chrome bore), about 5' long, blanked off on one end with a touch hole and mounted on some 24" steel wheels. All built by some Aggies that had moved down here. The bore was perfect for a steel beer can filled with cement. IIRC we used 1/2 of a beer can of black powder. (Our measuring device and projectiles both came from the ice house--- kept things simple)
