The caliber argument on here is ongoing. There is a daily question about which caliber is best for deer, elk, moose, hogs, you name it. But that' s what the forum is for I suppose! The answer most common on here is any reasonable caliber that you can shoot well. Shot placement is more important than caliber etc... I personally use a 45/70 for most of my hunting needs, sometimes something a little longer range, sometimes a .45 colt or a .44 mag. I would venture to say that if you are going after large hogs, anything in .270 or larger with a controlled expansion bullet would suffice. For smaller hogs, in this month' s issue of Guns and Ammo, Craig Boddinton took his daughter on a hunt in CA and used a .260 with great success, and chose the 7mm-08 as the gun that she would use in the future. Good luck with the hunt, and welcome to the forum!
I' ve hunted hogs in Cali more than a few times, and I would say that you better be prepared for some rather long shots. It is not uncommon to have opportunities presented out to 250 yards or so, and I would recommend the .308 class of cartridges (.260 Rem, 7mm-08 Rem and .308 Win), and the .30-06 class (.270 Win, .280 Rem, .30-06 and .338-06) as the best all-around choices. I hunted mostly with a .270 Wby Magnum and it did a fine job, so don' t exclude things like the 7mm Rem Mag.
Remember to use the heavier bullet weights for whatever you choose, and make sure they are of the controlled-expansion type. A .270 Win shooting 140-150gr bullets is a very good benchmark and you can base your decision off of that.
Well, the 300RUM would work. Only reason I don' t take it in WV is the 26" barrel. I know the CA hunting is different however. In WV, basically they are on a steep mountain with alot of briars with no shot over 30 yards. Not a place for a long barrels. I wouldn' t mind to try my hand at that long range hog hunting however