I have shot pigs with rifles ranging from the ridiculous to the sublime (22-250, 7X57, 30-30, 8mm Rem Mag, 375 H&H, and handguns all the way up to 45ACP). Any rifle that would be adequate for deer will kill pigs.
All calibers are marginal without proper placement, trajectory, and penetration. Some just give you more location options than others.
I do believe that is one of the most insightful remarks I have ever seen here on TFL.