I've lived in the South my entire life and never heard anyone refer to a shotgun as a "shotty". The only reference to shotty was when a southerner described something of poor quality as "shotty".

I think this original question, asked by a kid I believe, was properly answered. It is illegal to shoot from the road in mos(if not all) states and, unless the poster owned the property, would be considered poaching and tresspassing.