I have a nova scotia duck tolling retriever. He is 1 year old and is a excellent retriever in water/marsh. He retrieves bumpers and duck dummies, but he is still a bit hesitant with frozen birds. He refuses to fetch/scares when gun is fired...unless sound is a ways a way (1/2 mile). He is a great dog...just having some trouble getting him over this hurdle. any tips would be appreciated, thank you.