This year,on our lease, we killed 7 hogs. They ranged in size from about 350# to about 25#. All were shot the first few days of the the season, after that, nobody saw any more hogs-although there were some sign around. I got game cam shots of them around one of my feeders-but didn't see any during "hunting hours".
For eradication, some form of trapping has to be the answer. They are just too smart to hunt successfully, long enough, to do any good.