Here was a map I was working on a long time ago, that I never finished.
Maybe some people will find parts of it useful.
The major pieces of it were the Mouse controlled Turret/fire with Right Click, a somewhat collision detection on the projectile, and WASD controlled tank movement. Also the movement and fire doesnt work at the moment, so you have to stop to fire.
The idea of the game was going to be the Tron Tank game, but I got distracted by school and other games.