WARNING!!! This is an old fart waxing sentimental WARNING!!!
Is there a caliber limit? If not, I have just though of the weapon I would use if there where no semi-autos allowed, but it still retains the cartridge in the chamber, and uses no rockets, and is tacti-cool. The 106mm recoiless rifle. When my time ran out, and got out of active duty, I tried to to stay in the Navy, in the reserves. Having never been on a ship of my own, and the last two years of my hitch in the Navy's infantry branch, can't remember the name, I did like the fit in the Navy reserve, so I joined the Army reserve because I knew how to live on my feet, and like to have options if somebody shot a torpedo at me.. I was put onto a jeep mounted 106mm. How cool, a gun, hooked to a jeep. Imagine the possibilities. Personally fired a ton of rounds from one two Summer camps at McCoy. They eventually took them away and gave us Dragon or some other named anti-tank missile. Then, because of the cost, we were given one of them, and drew lots to see who would shoot it. Summer camp was never any fun after that. It took hale and hearty men to crew the 106, because when it went off, the blast concussion out the front and back was a real nut-rattler. Guys started out standing manly legs spread, and by the third shot, found comfort crouched down protecting the nads. Don't take my word for it, google 106mm recoiless rifle anti tank, they were on Marine Ontos too, 6 of them.