I guess the hogs I killed with Remington 55 gr. SP and Sierra 55 gr. SP, didn't get the message. When hunting with small caliber rifles/pistols. I treat them like i'm hunting with archery gear. Clean shot at the ear, or eyes. If I don't have a clean shot at the head, I don't shoot.

This is true. With the partition you can stick the bullet with confidence in the vitals/shoulder area. It will penetrate, and within reasonable distance and assuming the hog isn't cow size will exit!

That's what I'm going to stick to this weekend.

Been using the 77gr SMK exclusively for the past few years and no complaints...

In 5.56/223, I've had the best luck with 70gr Barnes TSX bullets for overall use.
It's plenty accurate out of my 16" 1/8 ARP 223 Wylde barrel and penetrates the hard stuff well.
If you have the luxury of plenty of time to set up a neck or head shot, you can be less picky on bullets.

That being said, in an AR platform there are much better caliber choices for pigs.

Didn't get a chance to use the 5.56 hog hunting unfortunately. I happened to have my 6.8 at the time while the other one was in the trailer. A 115 Nosler bthp planted a javelina though at a range of about 175 yards shot in the kneeling position. Never heard a bullet smack skin like that before.

I prefer heavy bullets. Lots of opinions and shot placement is key.

I have very good results with 70gr Hornady GMX and 65gr Sierra Game Kings.