Have you pig hunted in a area where you have a sounder of 15  20 pigs browsing around ?  Two accurate shots with a semi auto is not even an issue,  with a bolt action you are correct one shot one pig.
This is why I purchased the Browning BAR, Super fast, super accurate, and with a 308 more than enough to put a pig down with a single shot.   Then throw in the Fact the shots and not going to exceed 60 yards.  This is a pigtopia, Feral pigs, roaming around from ranch to ranch feeding and being hunted.
But as Grandma use to say the proof is in the pudding, I will be out December and hopefully I will have enough time with the BAR to work this double vision thing out.  If not I will go back to My BOSS and Pop one pig a hunt Just like you said MJB