Certainly an effective and relatively humane way of killing them. I wasn't aware of the extent of the problem, just that they were "there". There's some seriously big pigs in some of those herds, I can see where aggression would be a real problem.
Sometimes I really don't envy y'all down in the southern part of the continent, and this is one of those times. Having said that, there's really no reason why they couldn't move far enough north to affect us as well. We have a few farms here that raise Russian boar for meat, or some form of "sport" hunting.
What you have there is a problem, no question about it. Until I saw the size of the critters, I was thinking a .44 or .308 was some overkill, now I'm a believer.
Here's hoping the cost of ammo and sensible gun laws remain in your favour.
Sean