I take pigs at a rate averaging a few a week most often with .223. That being said, the range is never beyond 100yds with the average of 25yd.
I guess that I have a thoroughfare in my area and most of the time I am just waiting for them to cross my path as I wait in a dark spot.
I would suggest using expanding ammo meant for hunting and not the penetrating military type ammo.
I have a controversial bullet choice that is very effective in my specific situation, but I won't mention it here.