the way I trained my dogs is to take them out to a field and shoot a 22 pistol then give them a treat or do something your pup likes. Make them excited. Your goal is to let the dog enjoy the time outside, that there just happens to be a gun going off nearby. We sometimes might start with the dog 200 yrds away at the begining. By the end of training, my lab knew that he should watch the sky after that loud sound because his favorite treat was coming down. The worst thing you can do to a gun shy dog is put it near the gun. Soon everytime it sees the gun it will hide.

When we started with our pup, we started by clapping when he was eating dinner. Then we went to clapping two 2x4's together when he was eating. Then we started using a cap gun, and giving him treats. The most important thing to remember is to start slow and make sure he is haveing fun when your making noises.

i havn't tried this but, i heard that you can start at home when they are eating and make noise little by little not to scare it. also when outside have another person shoot the gun while you distract it by play or treats until the last 75 to 100 yards