There is a shotgun shell that contains no lead shot that is used to simulate a hunter shooting at ducks and such...... so that the retriever gets used to the sound. These shells are called "poppers" (blanks) and are louder than just taking the shot out of a regular shell, leaving the primer....... These poppers are about $6.50 to $15.00 USD per box of 25. What would any of you do if you wanted to try to make an electronic shotgun simulator...? How well could I approximate the sound of a shotgun......? A 12 gauge shotgun is approx. 150 decibels. D.