Gunfire
A pup that is bird crazy is easy to gun break. Not until the pup is flushing and chasing birds with confidence, do we introduce gunfire. But we start way before by making loud noises; banging food pans, doors and etc. to socialize a young pup to gunfire. Soon the pup has advanced to where he knows the sound of the cap gun means a "dead bird" and he will advance quickly to actually shooting birds over him.