I don't know of a way to fix a dog that's become gunshy. I'm also not an expert, so take my advice for what it's worth. I raise beagles and hounds. I have always been careful about how I introduce a pup to gunfire. For my type of dog, I simply take them hunting. I only take them with my dad or my brother in law, who basically owns the other half of our pack. We have a rule when a pup accompanies us and that is, nobody shoots unless that pup is in the chase. If he's not barking, the rabbit won't be in danger.
I've used this technique for every pup I have ever raised and it's been probably 98% effective. Now,I think the dog you have may be some type of retriever, and since he won't get as excited and be making noise himself, this probably wouldn't have worked.

There's also the factor of the pup's demeanor and personality. I have a year old male beagle that got shot around when he was about 4 months old. He was far away and in the pen when it happened, but after the shot, I heard him bark. I turned around and walked back there and he was jumping around all curious about the sound and such. It helped because he was in a pen with his momma who knew what a gun was and would quiver with excitement whenever she heard a shot. I watched him while my dad continued to shoot. He loved it. So, I leashed him and took him closer to the shooting. The closer we got, the more excited he became....dancing around and tugging at the leash. I eventually let him go right up beside dad and the silly pup would try and catch the spent shells when Dad ejected them. He's the only dog I've ever owned that reacted like this. Most times, if the shooting is far away, it won't bother them much. Shooting over their heads before they've ever heard it is a no no though.

I wonder if your dog ws put off because of new people. Could it be possible that new folks making lots of noise was just too much for him?


GH