The gun I was to handle was an old-model Terran Federation Army infantry-platoon accompanying gun. The mount, however, was power-driven, like the mount for a 90-mm contragravity tank gun. Reconciling the firing mechanism of the former with the elevating and traversing gear of the latter had produced one of the craziest pieces of machinery that ever gave an ordnance engineer nightmares. It was a local job, of course. An ordnance engineer in Port Sandor doesn't really have to be a raving maniac, but it's a help.
Externally, the firing mechanism consisted of a pistol grip and trigger, which looked all right to me. The sight was a standard binocular light-gun sight, with a spongeplastic mask to save the gunner from a pair of black eyes every time he fired it. The elevating and traversing gear was combined in one lever on a ball-and-socket joint. You could move the gun diagonally in any direction in one motion, but you had to push or pull the opposite way. Something would go plonk when the trigger was pulled on an empty chamber, so I did some dry practice at the crests of waves.
"Now, mind," Tom was telling me, "this is a lot different from a pistol."
"So I notice," I replied. I had also noticed that every time I got the cross hairs on anything and squeezed the trigger, they were on something else when the trigger went plonk. "All this gun needs is another lever, to control the motion of the ship."
"Oh, that only makes it more fun," Tom told me.
Then he loaded in a clip of five rounds, big expensive-looking cartridges a foot long, with bottle-neck cases and pointed shells.
The targets were regular tallow-wax skins, blown up and weighted at one end so that they would float upright. He yelled into the intercom, and one was chucked overboard ahead. A moment later, I saw it bobbing away astern of us. I put my face into the sight-mask, caught it, centered the cross hairs, and squeezed. The gun gave a thunderclap and recoiled past me, and when I pulled my face out of the mask, I saw a column of water and spray about fifty feet left and a hundred yards over.
"You won't put any wax in the hold with that kind of shooting," Tom told me.
I fired again. This time, there was no effect at all that I could see. The shell must have gone away over and hit the water a couple of miles astern. Before Tom could make any comment on that shot, I let off another, and this time I hit the water directly in front of the bobbing wax skin. Good line shot, but away short.
"Well, you scared him, anyhow," Tom said, in mock commendation.