Today's Notes from the Technology Underground includes a report on the Idaho Boomershoot! 2006. This event involves people target shooting with high power rifles and from distances of up to 700 yards. The twist is that the targets are reactive (that's where the boom! comes in). The web site is packed with interesting stuff. I recommend the video journal, which gives a nice overview of the shoot.
BTW, it does appear that the explosives are manufactured, stored, and controlled by a BATFE licensed person. However, it doesn't appear you need a license to shoot the explosives :)