Banging the feed pan makes the dog bolder to noise. association with bird and gun fire comes much latter after the drive has been established.
(If you want to make a gun dog). if you want to make a field trial dog getting them steady to the flush and wing and shot you train in a way that the shot does not matter. slight bang during whoa breaking and then graduating to a blank pistol during check cord exercises with pigeons orquail in a trap. you shoot while dog is on point several times so that when you flush the bird the shot does not matter. they are still standing on point.
Bird dogs are a privilege to own and the preservation of the habitat and the upland birds are of the upmost importance. As a sportsman it is your duty to preserve the heritage of the dogs and the game. I encourage you not to disturb the birds during nesting and raising time.
Throughout most of the country it is against the law to train dogs on wild upland game during this time. In most states that pro trainers go during the summer a permit is needed to train. Also no dogs can be run until August 1st; August 15 in some.
If you feel that you need to do something with the dog during these months try a recall pen with birds you buy from a grower or pigeons