The Banana Gun has six chambers. A single seed-pod forms in a single chamber as the Banana Gun ripens. When it has reached full development, under a bright sun, the Banana Gun begins to 'trigger' itself, cycling its cylinder counter-clockwise until it reaches the random chamber the explosive seed-pod is in. When that happens, seeds and banana fruit expel at a very high velocity, and can be deadly if you are in range. You can also pull their 'trigger' yourself with the same effect. If you intend to use the Banana Gun in this fashion, it's recommended to peel back the end of the 'muzzle' slightly, to prevent a backfire.
It is for these reasons that the Apples pick Banana Guns just before ripeness, to be used in their evil game.
Banana Guns grow on trees.