Personally I would not do it quite yet. And if I did at quite a distance by someone else and see if he notices it. If he doesn't, a bit closer. If he notices it, take him over, let him smell the gunsmoke and gun oil, and give him a treat.

Siegfried knew if I smelt of gunsmoke and/or gun oil and would start doing backward spins and twirls in excitement. "We were going shooting!" Even if I had only handled a firearm in the house.

His introduction to gun fire was by accident. About this time of the year when I had planted a fresh hay crop, galah parrots (native parrots which can be legally shot on crops) would sit on the field a lot and eat the newly planted seed. So lots of shotgun 'work' to do. Seeing maybe a hundred birds on the field I grabbed the gun and ran down and fired off a couple shots. "EEEK" I heard 50 metres behind me. Of course Siegfried had followed and scared by the gun was running frightened back towards home. I called and he stopped and I got him to sit. Came over and patted him, reassured him, let him smell the rifle, reassuring him the whole time. Then off home for a treat.

Next time did it on purpose with a .22. Not a flicker from him. A treat. Two or three goes later a shotgun. Not fear.

Not an expert at all, so if anyone disagrees with how I did it, please tell.

Peter's use of other dogs is a very good method. We used to train our sheep dogs with older sheep dogs. Much quicker and easier to train a puppy if a well trained older dog is available. The young ones watch their older peers and learn from them. Good habits as well as BAD habits! So pick the their peers well.