This mod is pretty good for a first-mod. It replaces the hand canoneer icon, and gives it more of an explosion when firing. The shooting sound is also changed to a machine gun. The icon is a bit grainy, due to palette limitations, but otherwise okay. The explosion is a bit fake, but it's good if you aren't looking directly at it. The machine gun sound is superb.
If you are ever making a terrorist scenario, download this mod.