[T. O'Heir]

"...possible to hunt larger game..." That has nothing to do with it being an AR or not.
The bullet weight and its construction matters most. There are lots of good .223" deer bullets around. Think in the 70 grain hunting bullet area for weight.
What you can hunt with a .223 depends on where you are. It's most States not some that disallow .223 for deer. The .223 is essentially a varmint cartridge in the States where it's illegal for deer sized game.
Hogs come in assorted sizes, so how big they get locally will determine how suitable a .223 will be for 'em. Porky can go to 400 lbs. in some places. More about shot placement and a bullet that'll penetrate(that's a deer bullet) vs expand rapidly upon impact(that's a varmint bullet).
Your 16" rifle needs to be up to the accuracy required for hunting varmints too. How accurate depends on the varmint. 2" or less at 100 for stuff like ground hogs and coyotes. With any rifle, it'll matter if you're reloading or not too. Milsurp FMJ ammo is not allowed in most places.
If you're not reloading, you'll have to try a box of as many brands as you can to find the ammo your rifle shoots best. The price of it means nothing either.