Black Hills 69 grain BTHP
I killed the last several pigs in my pasture with Black Hills 69 grain BTHPs. Shoot them in heart/lung, does the job. Blood loss is adequate to quickly cause shock and drop them, they don't go far.
Sometimes I use 75 grain BTHP, I just bought a box of Barnes 62 grain to try.
As soon as my 7.62 SDN6 suppressor transfer is approved, I plan to try a SBR .300 blackout and see how well it works.
I would advise a bigger caliber than 5.56 if this is a special hunt you're paying for or if it will be tough to make a decent shot under 100 yards.
I have dozens of black rifles, both carbine 5.56 & battle rifle .308. I've killed more hogs & deer with my Marlin 30-30 than all of the rest put together. Practice a lot of very quick target aquisition shots (simulate short stops like a rooting hog does) because shot placement is key to killing versus wounding. I practice on clay pigeons (black side) set on a sand pile, it's about the right size kill zone and you know when you hit it. Prior to hunting, look at a diagram of where the heart/lung is on a standing hog if you've never butchered one so you know where to aim at. It's the third shirt button from the top :)
I have switched to the AR15 with night vision, easier than holding 30-30 in one hand and spotlight in other.
good luck,
RFA