Mobile Suit Gundam 00 is the fourteenth television series in the Gundam franchise (dating back to 1979). It represents several landmarks for the franchise, being the first Gundam title to take place in the Anno Domini era and the first Gundam television series to be broadcast in high definition and a widescreen format. 00 is also unusual in that while most Gundam series consist of a single 45 to 55 episode season, 00 is split into two separate 25 episode seasons.
The following firearms are seen in the anime series Mobile Suit Gundam 00:
In "Twistedness of Innocence" (S02E08), Tieria Erde carries an unidentified pocket revolver in his stocking while infiltrating a party dressed as a woman.
A fictional submachine gun is seen in the hands of armed mercenaries in "Return of the Saint" (S01E13). Its design (At least the magazine well and magazine) resembles the Arsenal Shipka.
During the closing credit sequence in Season 2, Setsuna is seen walking through a battlefield with hundreds of graves marked by rifles buried in the ground, many of which are AK-47 rifles.
Most of the assault rifles seen in the series are a fictional rifle based heavily on the Kalashnikov design. The gas block has been flipped so that the gas tube runs underneath the barrel (similar to the AN-94), the bolt is operated via a tab located slightly behind the ejection port, and the stock is a thumbhole design similar to the stock on a SVD Dragunov. Some of these rifles have bayonets affixed to the barrels.
In "Return Of The Saint" (S01E13), Lockon uses a Sako TRG-42 (outfitted with a birdcage style flash hider and a bipod different from the standard TRG bipod, as well as some sort of cover over the barrel underneath the scope) from the cockpit of Gundam GN-002.
A number of GE M61 Vulcan machine guns housed in futuristic versions of the Phalanx CIWS are seen during a demonstration of the AEU-09 Enact mobile suit in S1E01.
During the siege on the Africa Tower orbital elevator, some of Hercury's men guarding the lift trains are armed with fictional light machine guns with drum magazines.