A different approach... (Score 1)

Since AOL makes free CDs so readily available, use a stack of 100 super glued together as the projectile. A large pvc tube slightly larger than a CD would work good. Using the same design as a potato gun, have a chamber at the bottom to fill with gas and ignite. This should send the stack flying somewhere fast and hard. Fun enhancement: 1. Mount a spike through the center of the CD's (please don't try this at home) 2. Dremel slightly spiraled ruts down the side of the glued spindel. Should add a slight amount of spin and increase distance. 3. Fill the center of the CD's with a "message in a bottle" and cap off the ends before firing. This would be lovely for exchanging threats in a high impact manner.