Friend of mine uses his 10mm auto or a .44 mag.
Other friend of mine uses his single shot .45-70, a .30-06 or his 12ga.
A 12ga shotgun with slugs or buckshot (if you're close) should be fine. A .30-30 or bigger rifle would do it too.
My second friend's sister went with him once (he lives on 90 acres of forest with a large herd of wild/feral pigs) with a shotgun to back him up, a 300-lb pig came right at her. She accidentally dropped the 870, ripped out her Bersa .380 and hit it five times with Golden Sabers. Good aim, good performance and it died quick. Used to my Bersa, sold it to him, she shot it and never let him have it back. ;f
"And Shepherds we shall be. For thee, my Lord for thee. Power hath descended forth from thy hand, that our feet may swiftly carry out thy command. So we shall flow a river forth to thee and teeming with souls shall it ever be. In nomine Patris, et fili, et Spiritus Sancti. Amen."