Double Naught Spy is correct in that statement for the most part. Right behind the ear can, and usually will be, a good shot but there is a good bit of room there for error. Especially with a .223 caliber bullet. Falcon brought up the yawing effect that is inherent to most .223 caliber bullets. And unless it is a monster hog that bullet won't be into a yaw by the time it is in the spinal area. The yaw is why the .223 can be such an effective round when placed properly. When you start using bullets like the TSX or TTSX Barnes bullets, from all the results I have seen, they don't yaw like the Military ball ammo. So their effectiveness comes from expansion rather than yawing and fragmenting. While I am nowhere near the hog exterminator the old man was, he did take myself and my siblings on many hog hunts and we all have quite a number of hogs under our belts. Like the old man, my preferred rifle is my AR 15 in 6.8spc but I have on many occasions used my little WC AR15 in .223 with hand loaded 60 grain hornady SP. They do a pretty good number on a hog when hit right. But I am in pretty much agreement with Oldtimr on this, the .223 is not a cartridge I would want to start a hog hunter out with. It's just too iffy of a round to trust in the hands of a beginner. I wouldn't want even a hog to suffer needlessly. The .223 is best left to those with plenty of experience in my opinion. Like Falcon, I've killed the things with everything from .22 shorts all the way up to my dads .50 caliber Barrett at 580 yards and boy was that a mess. Had pick up most of that hog with a spatula. The old man didn't think that bullet would even open at that range. He thought wrong.