Patterning a shotgun shows you what a specific shotgun and specific shells will do regarding the spread and pattern of the projectiles hitting their target at various realistic distances.
If you are relying on a shotgun for defensive purposes and you have not patterned your shotgun using ranges from 5y to further than you would normally engage you are wrong.
If you are relying on a shotgun for defensive purposes and you have not patterned your shotgun using ranges from 5y to further than you would normally engage you are wrong.