I used a "Lucky Dog" dummy launcher to condition 5 dogs to gun fire (3 Drahts, a Pudel Pointer and a Teckel). They shoot a retrieving bumper. I let the younger dogs watch from a distance as the older dog gets the retrieve of a bumper just shot. The pup gets both the sound of a shot and observe the bumper flying through the air. It works great in my opinion. All the dogs loose their minds when I pull out the launcher now. Now they are like a good Soldier running towards the sound of gun fire. We had a blow out on a trailer doing yard work and all 3 dogs ran out the fence out into the pasture looking for something to bring back.