every seen a calico firearm? they were ahead of their time but faded away with tighter gun laws. they had a spiral feed mag, their .22 held 100 rounds.
video
http://www.youtube.com/watch?v=-bxE6MZlxGQ&feature=related
video
http://www.youtube.com/watch?v=-bxE6MZlxGQ&feature=related