[Vision]

Single, double, buckshot. Could back it up with a slug, but a slug will just go through a guy. Buckshot will do the same at close range but still have lots of room for error out to 40 yards.

[RightWhale]

That is the correct series of loads. Also, practice shooting from the hip. Recoil becomes not a problem, and you have a couple more feet to swing around. Push the muzzle down and away to compensate for line of aim. This is most important if it is dark.