You're right! It terrifies birds!
"The 'Bazooka,'" explains contributor Mark Holloway, "is at the place where I deliver cottonseed in Coachella, California. When it fires, it sounds like a cannon!" The Bazooka is used to scare birds off piles of corn like the one in the picture at the left. You can tell the Bazooka just went off, because otherwise the pile of corn would look more like the one below.