The 10-feet long, 2-in barreled weapon, called the Punt Gun, is the longest shotgun in the world.

In the late 1800s, a hunter could use this gun to sneak up on a raft of sleeping ducks, fire a single shot (which consists of 2 lb of BB pellets) and kill nearly 100 ducks with a single round!

TechEBlog has the larger pic and video: Link