The Union Iron clad U.S.S. Cairo was sunk by a Confederate torpedo (mine) in the Yazoo river near Vicksburg in December 1862. The Cairo was salvaged in 1964. Because the Cairo was buried in silt and mud much of ship and its equipment was preserved. The ship is now on display at the Vicksburg National Military Park, Vicksburg, MS.
One of the guns now on display that was aboard the Cairo is an Army M-1814 42-pounder Army rifle on modified naval gun truck. Instead of using a quin for elevation, the original elevating screw from the field gun carriage was used.
The one complete firing cannon that I have right now is a model of this gun.
I bought the plans for this gun from the Late William Green. Mr. Green’s plans were for a small gun, but I scaled up the plans for a one-inch bore. I used a 6-inch diameter piece of 4140 to make the tube. Yes that nasty stringy stuff. I drilled the bore, then honed it smooth. The trunnions were threaded, then weld on,
The truck is made of maple and is covered with marine spar varnish.
I built a mould that casts a 7-oz hollow based slug shaped like a long air gun pellet. 300 grs. Of FG drives the slug down ranges.
The first time I fired the gun it flipped on its back, I made an arresting system. I rigged a double block system on both sides of the gun truck. I drive some large bridge spikes into the ground and attach the free end of tackle to these spikes. The running end of the rope the attaches to the rear of the truck
By the way look at the picture posted above of the gun at rest and firing. Notice the position of the rope. Compare it with picture below of the gun in full recoil. That little gun moves when fired!