I'm going to be hunting deer next month with Dogs in Southhampton County Virginia. We have to use buckshot and I've never killed a deer with a shotgun. I'd like to use my Beretta 391 Urika 20 gauge which I prefer to my Mossberg 500 12 gauge. Without going into details, the Beretta is a finer gun. If I can hit quail and dove, Deer should be no problem. However, a deer is a much larger animal and a clean kill is a necessity. Anybody use a 20 gauge for deer. What ammo? What choke? Thanks.