My friends & I have accounted for several hundred hogs spanning nearly 30 years of hunting/shooting & have used a variety of calibers in rifles shotguns & pistols for this very purpose. One mate swears by his 222( slightly under your 223) & he has nailed some huge 300+ pound boars, but generally with head shots. I have also seen on the rare occassion a big boar with caked on dried mud hit in the shoulder with a 223, only to take off like it wasn't touched. The boar was finally shot & the initial 223 shot examined. The bullet had made a 3 inch diameter crater, about an inch & half deep. I find that the 223 will drop even the biggest boars with head shots at whatever distances you are capable of shooting at. Medium boars will also fall to chest shots with the 223. I think the downfall of most 22 centerfire rifles if used for feral pig eradication is that if a pig, or a mob of pigs, is running directly away from you they lack the instantainous killing power that a 30 calibre offers in arse shots. Sure your 223 will anchor almost any size hog but I wouldn't be going out specially to buy one for the job.