While clearing the newly-liberated UNF HQ, several UNF soldiers are seen carrying Glocks with tactical lights mounted to the forward frame. While the Glocks shown are obviously full-sized models, the scenes are not clear enough to identify an exact model number.
Rifles
M16 Rifle
The majority of UNF soldiers carry M16A4 rifles, distinguishable as such by the flat-top receivers. The M16s seen have several unusual configurations, but all have flip-up front sights as opposed to the normal blade sight.
AKM
A few militia fighters in Uddiyana are seen carrying AKM rifles.
Shortened AKMS
Ru Pou's soldiers are seen carrying shortened AKMS rifles.
AK-74
Most of the milita fighters in Uddiyana are seen carrying AK-74 rifles
AK-74M
A single militia soldier is seen carrying an AK-74M.
The UNF LAV-25 mentioned above can be seen outfitted with an M242 Bushmaster chaingun as its' primary armament.
GAU-19/A
The HAVWC units operated by SDC are all equipped with a single GAU-19/A minigun under the "nose" of the mecha.
GE M134
The VTOLs used to transport the HAVWC units are all equipped with a set of M134 Miniguns.
Other
HAVWC Sniper Cannon
When a mission calls for a HAVWC to be able to deliver accurate fire over a long distance, the crew of SDC retrofits a large anti-armor cannon to be used as a makeshift sniper rifle by a HAVWC unit. The weapon is depicted as firing a gargantuan, multi-stage explosive shell. The notion that the HAVWCs are some sort of super-robots is thrown out the window, as the SDC techs spend an entire episode calibrating the HAVWC's systems to be able to withstand the weapon's weight and recoil while still being accurate. Never the less, the weapon's recoil proves to be too much for the HAVWC, and causes the recoil dampers in its legs to overheat.