we havent seen any snakes about the house for a few years. in fact i think we have only seen 1 dead baby brown (thats scary - 1 must mean more plus mum).
DH doesnt use a .22, too easy to miss! 12 guage all the way we have red bellies, browns and tigers on the place.
apparently black snakes keep brown numbers down (they eat them apparently) and are less venomous then browns.