That is a bit odd that the state will only allow #2 or smaller shot for hunting animals, birds sure, I can see them limiting the shot size. The shot will kill a hog but your going to need to be close to do it. I think most people using a shotgun for game would use slugs or buck shot, I would. I think you should double check the regulations or better yet call F&G and ask them directly.
I just copied this from the Georgia F&G web page.
LEGAL FIREARMS &
ARCHERY EQUIPMENT
ARCHERY:
Longbows, recurve bows, and
compound bows are allowed for hunting any
game or feral hog.
Crossbows are allowed
for hunting feral hog and any game except
waterfowl. Arrows for hunting deer, bear or
feral hog must be broadhead type.
CONVICTED FELONS
may not possess any
firearm while hunting unless that individual’s right
to carry has been restored (OCGA 16-11-131).
This does not apply to archery equipment.
DEER & BEAR FIREARMS
: Modern Rifles
and Handguns
: Centerfire Only, .22-cal. or larger
with expanding bullets.
Shotguns
: 20-gauge or larger loaded with slugs
or buckshot. Buckshot is not allowed on WMAs,
unless otherwise specified.
Muzzleloaders:
.44-cal. or larger, or
muzzleloading shotguns 20 gauge or larger.
Scopes are legal.
Primitive Weapons:
Legal weapons during
primitive weapons season include crossbows,
bow and arrow, and muzzleloading firearm.
Scopes are legal.
TURKEY FIREARMS:
Shotguns with No. 2 or
smaller shot and any muzzleloading firearm.
FERAL HOG FIREARMS:
Any deer, bear,
turkey or small game firearms.
SMALL GAME & FURBEARER FIREARMS:
Rifles and Handguns:
Any .22-cal. or smaller
rimfire, air rifle, or any muzzleloading firearm.
Shotguns
: Any having shot shell size 3.5
inches or smaller in length with No. 2 or
smaller shot.
Shotguns (Waterfowl):
Any 10-gauge or
smaller loaded with federally approved nontoxic
shot of size “F” or smaller. Lead shot may not be
in possession while hunting waterfowl.
SPECIAL FIREARM RESTRICTIONS:
Plugged Shotguns:
Shotguns must be
plugged to a maximum capacity of 3 shells
(magazine and chamber combined) except for
deer, bear & feral hog hunting. For deer, bear
& feral hog hunting, shotguns are limited to 5
shells. Plugs must be one piece and incapable
of being removed through the loading end of
the magazine.
Looks like the #2 shot restriction applies to turkey hunting only, but I did notice that they don't allow buckshot when hunting the WMA,s unless specificaly allowed, so I would sugest your buddy buy a couple of different brands of slugs and shoot them to see which shoots best and then go clobber some hogs.