[Andy A.]

A hopper is a bucket you dump stuff into.

A magazine is a hopper with organization. Instead of just getting dumped into a bucket, the balls are placed into a tube one on top of another so they stay organized and could be fed into a mechanism, like a gun, in a controlled fashion. The tube magazine is just an example.

Another example; A paintball gun has a hopper that you dump balls into. typically, the hopper sits over the firing mechanism of the gun, and gravity feeds the balls through a tube into the chamber. In a modern rifle, bullets are usually placed below the firing mechanism in a 'box magazine. The magazine, sometimes called a clip, is spring loaded and forces the bullets up to the top of the box where the gun then grabs them and moves them to the chamber.

The hopper works for the paintball gun because the paint balls are small and spherical, so theres no wrong way for them to enter the chamber. A bullet is very different in that it is an odd shape, and it has to remain in a very fixed orientation, or things go boom in a bad way. In fact, poorly made magazines can cause guns to jam easily, since a bullet may not be in exactly the right position when the receiver goes to extract it from the magazine.

So I guess the real question is, how organized do you plan on keeping the balls in your 'bot?