The following weapons were used in the OVA Amaim Warrior at the Borderline: UltraSteel Ogre-Gear:

Assault Rifles

Futurized M16

Hinukan fighters use futurized M16s, similar to the Yatagarasu using them in the original AMAIM anime.

A Hinukan fighter with his M16 in the first episode.

What appears to be a Barrett M82A2 is used by a Hinukan fighter in the first episode.

Barrett M82A2 with riflescope - .50 BMG

A Hinukan fighter aiming the M82A2 in the first episode.

The Mk 153 SMAW is seen with Hinukan resistance fighters. Unlike AMAIM, this one has a carry handle depicted.

Collapsed Mk 153 Mod 0 SMAW - 83mm

A Hinukan fighter aiming the SMAW in the first episode.

Chinen Ibuki with the SMAW fired on a hostile AMAIM in the third episode.

Shot of the square sight.

An autocannon is used by Hinukan fighters in an armored 4x4 vehicle.

The 4x4 vehicle used by Hinukan in the first episode.

The M61 Vulcan is seen in the OVA mounted on Oceanian Bunyip Gingas and the Dreadnoughtus truck used to transport Jin Misawa's Proto Gouyo.

GE M61A1 Vulcan Cannon - 20x102mm

Diagonistic image of an Oceanian Bunyip Ginga in the first episode.

The Vulcan on the Ginga's right shoulder.

Jin doing a hero moment while standing on top of a Dreadnoughtus truck.

The M61 on Jin's Dreadnoughtus being fired in the second episode.

The Dreadnoughtus rushes in to take out hostile AMAIMs in the third episode.