The present invention is directed toward a magazine for loading paintballs into a guppy. The magazine is in the form of a tapered plastic container defining a chamber, an exit port leading from the chamber and a top loading opening leading to the chamber. A cover is snap mounted to the container and a paintball feed mechanism is mounted adjacent the bottom of the container next to the port. The feed mechanism comprising a slide housing mounted to the container and a slide member defining a beveled aperture sidably mounted in the slide housing, the slide member being spring biased in a closed position to provide selective access to paintballs held in the container chamber allowing a guppy to be mounted to a guppy support member which extends away from the feed mechanism to be loaded with paintballs.