You didn't say anything about how the test firing went.
I didn't get to fire it much but I can tell you right now my attention will be focused on some sort of sighting system next. I made up 4 sabots consting of a 2 1/2 inch long of dowel rod with a lead ball attached. The water heater in the pic is at about 20 yards. Two of the four actually hit it. One is at the grass line and the last one in almost center. Two completely missed.
I was supprised at how little it recoiled. I was using 350 grains of 1F with the sabot and it only moved about 8 or 9 inches. The steel carrage must have helped absorb the recoil. I think I will up the charge some next time.
I dug one of the balls out of the dirt behind the water heater. The dirt was not packed hard and the ball managed to penetrate 18 to 20 inches.
