Would love to see pix of this.I built my bowling ball mortar on a steel sled which works really well for recoil retardation.The swivel base is bolted to 5/8s thick steel plate backed by two, 3 x 16 inch thick glue lam deck fitted cross ways on the steel sled box. I welded four heavy steel loop handles , two to the side of the steel box so four men can lift it into the pick up box. I'd guess total weight is 200-250 lbs.
I made mine with a 27 inch tube and the ignition is a musket cap and nipple directed into a steel powder chamber threaded into the neck of the tube from the inside. It is lanyard fired so I can get away from standing next to it.
The barrel and base sled come apart if necessary with a 1 x 9 inch hardened tool steel base pin. I bent the first one left non- hardened. Range is estimated between a 1/4 and 1/2 mile based on the occasional ball retrieval.
Flight time at about 20 degrees from vertical is about 17 seconds and the ball just about goes out of sight before the turn back to earth. The finger holes in the ball whistle all the way up and back. Pretty cool and I never get tired of watching the balls fly or the look on folks faces that are watching. The main trouble is finding a safe place long enough to shoot it and being mindful of any air craft in the area.
Guess that would be dependant of what's out there when you reach the "alarming distance". Is it alarming because of what is out there that you may not want to hit? LOLThanks, Tanglefoot. I recall a tale of a cannon using concrete filled cans for projectiles; apparently enough of a void existed in the concrete in one to allow it to expand Minie-style and travel an alarming distance. That sounds like my kind of fun.