If i had to use a 223, i would use a 60 gr. nosler partition and shoot for the neck. I would not go for a shoulder shot unless the pig was a small sow. The neck shot with a high speed bullet causes a hydrostatic shock that will disrupt the nervous system. Hogs i have shot this way have gone down on the spot, not to get up again. I will say though, i have never shot a hog with a 223. Keep the shots close, so as to keep velositys high for that shock effect. Just my 2 cents worth.