cataraft

Thanks for the vote of confidence, its nice to be supported for agreeing with the professional recommendation and sharing my own personal experience watching others shoot hogs. We can't all be Ivory Towers I guess.
Any cartridge will work if its a perfect shot-- that's not even worth saying. Hunting is seldom perfect. I have seldom seen a good first shot fail with any cartridge. It is the second, third, and fourth hog that is running that gives you trouble or the one that is already on the move and quartering. Many of the hogs that I've shot were on the move and required me to move with them to get into position. There is nothing basic about that type of hunting or shooting. It can be very difficult and challenging shooting-- that's why there is an Olympic sport based on it called the biathlon. At other times you can walk right up and just pop em. I think that is why I enjoy hunting them because every time I go I get a good variety of opportunities and it builds on my hunting and shooting experience. Hunting hogs I've had the opportunity to take every imaginable kind of shot from 5 feet to 300 plus yards, running, standing, feeding, etc. some very difficult and some very easy. Because of this I carry a rifle that will do anything I may choose to ask of it.
My point is that anything from .22 up through 7mm has been proven to kill when things are right but that a .30 will work better when things aren't. And things often aren't perfect.
The guide recommended a .30 because he knows from experience that it is the best killer under all possible conditions and angles and the surest bet to cover all bases without knowing the hunter's ability and experience. I agree with that recommendation because experience in the field has proven it true for me as well.