have you shot the 30 06? if you can shoot it well i would use it with some fmj ammo easy to find and cheap. full metal jacket ammo will not expand and will leave small holes in the pelt. but if you havent shot it or dont fell comftable shooting it i would use the 12gage or the 20gage with a full choke and #4 buckshot but if you use the shot gun and buckshot limit your shots to 50yds hope this helps. if you havent shot the 30 06 ask your dad if he will take you out and let you try it. if you like it that would be the way to go. good luck! let me know how it goes.