Anything that you can shoot well will work. It all depends on what size exit hole that you want.
I do not want any exits, many of the pigs i shoot are literaly underfoot of cattle. so I have used a variety of .223 ammo, all with excellent results. My favorite pig cartridge tends to cause an uproar, so, again I won't get into the specifics. But, I will say that my favored cartridge lays them down in place.
Navin R. Johnson: "He hates these cans!!!! Stay away from the cans!!!!"