I've only killed 4 in my life. That was last year at the 24Hr Hog hunt. All were head and neck shots with a 30-06. All of them went down, however, one of them I got high on the neck and was still alive and had to shoot it again. I think most of the guys on the hunt recommended the head or neck, so that where I placed them.
This year I'll be using a 300 Blackout with 110gr TTSX's. I hope I'll have good results but I'm a little worried. I'm not sure if I should try the shoulder or not. I found the neck is a big enough target, but as captdavid said, they don't stop moving. Wish me luck, we'll be perforating pigs Thursday through Saturday this week.