Saw an ad in field & stream for Gamo air rifles. The ad (I will double check if I can) claims to have taken down a 300 lb. hog with spec. ammo.
So looked on their web site and found a vid. But in the vid he states it's a 180 lb. hog, that's still hard to belive but here is the vid.
http://www.gamousa.com//Videos/62_wmv.htm