Certainly one of the most unusual-looking guns to come out is the Mossberg 500 Chainsaw. Built in the iconic Mossberg 500 action, the Chainsaw is a pistol-grip pump-action shotgun with no stock. While guns like this are desirable for home defense, they're notoriously hard to control while firing, a problem that Mossberg has solved by attaching a wrap-around chainsaw-style hand grip to the pump.