I'm not a big fan of buckshot so I would say a slug. Most guns will shoot a rifled slug out to 70 yards pretty well. Sights would help quite a bit though.

Just make sure you get rifled slugs because the fins will collapse when they go thru the choke. For 2-3 dollars a box it couldn't hurt to try them and see what happens.

I agree with the others, if you want longer range and more accuracy get a rilfed barrel and possibly a scope. The down side is saboted slugs are 10 bucks and up for 5 rounds! I just got some federals with the barnes exanders and it cost me 41 bucks for 15 rounds!!

Paul