If you are hunting in a blind with a feeder, trying to kill 1 hog, the 5.56 ought to drop any pig with a head/spine shot. I suggest the 70 grain tsx bullet if your barrel has a 1:7 twist (1:9 can't stabilize that heavy of a bullet). Basically if it's gonna be an easy shot and u think u could hit the hog exactly where u want to then you should be fine. A .22 lr will drop a hog with a perfectly placed shot. But a larger round will drop the same pig with an extra inch or two room for error and less than perfect shot placement. If your barrel won't stabilize the 70 grain ammo, try a 62-64 grain bonded bullet like the Winchester razor back xt, federal fusion or an expanding soft point round. Just done use varmint/fragmenting ammo. It won't penetrate deep enough to reach the vitals before it breaks into pieces and you'll be left with a mad hog with a nasty shallow wound. Fmj and steel core ammo like the 62 grain m855 will penetrate deeply, which is good, but it won't open up and leave a larger wound channel like an expanding bonded bullet.