Considering the average razorbacks has 4" tusks, you are approaching them on equal terms.
The guided hog hunts in North Carolina seem to prefer 12 bowies, which would still be danger close for the average hunter. The particular difficulty is to penetrate an extremely tough ribcage scarred from numerous conflicts and reach the heart, which in a 250# plus hog can be more than 4 inches deep. A large heavy knife seems to be the choice among those who want to go hand to hoof.
In Europe even the local prince equipped his beaters with 6-8 foot boar spears, which, given the slight regard for peasants in the day, still speaks volumes about the inherent risks.
I understand it's always open season for feral hogs in CA and MO - I'd go with a general hunting tag and a magnum pistol with 8" barrel and low power scope, and leave the knife for processing (which is problematic with the typical diseases endemic is some populations.)