The trouble with pigs is the range in size. Most calibers will handle mob pigs under 100lb. But I can almost guarantee like 90% of hunters, when you see a mob you will not be able to help yourself in going for the biggest! Its understandable. I have seen a 180lb boar stop a .270 projectile with its shield and shoulder blade. But thats also a rare event.
Get a 6.5 of some sort ( Grendel,Creedmoor, .260 or 6.5x55) would be my advice. Its not too big, but you can use it for pigs, deer goats and maybe some small game if you wish.
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