They do the same thing on public land in Arkansas. Goal is to keep a group of hunters from setting up and sky blasting all day long and harassing the ducks and other hunters. Encourages folks to THINK about their shots. Its public land and they are trying to make the best experience for all and also help manage the resource. Great concept to keep it a free for all and to open it up to everything for everyone all the time, but the reality of that type of situation creates chaos and a degraded experience for most. The locals I have talked to in Arkansas like the box or shells or less on public land rule.

Side note - Heading north across the TN river on 65 on Sat AM about 7:30, I saw a flight of about 25 Sandhill Cranes.