The Desert Eagle MK VII is labeled as a .44 in the game. It starts with a eight round magazine, but can be upgraded to 12 rounds. Capable of blowing an enemy's head off in one shot. It is the sidearm of Breznev.
Rios and Salem start with Heckler & Koch G36Cs. It is also used by FDI mercenaries early in the game and can be picked up from them. JD also carries one. Can be modded into an MG36.
The AK-47 is one of the weapons available from the start. Breznev is shown using this weapon in cutscenes. It seems to have a AKS-74U muzzle device attached to it as standard.
Shotguns are powerful weapons in AO2:40D, having amazing stopping power and the ability to blow up heads. This advantage is sacrificed by three factors: Pellet spray, reload speed, and Aggro.
Molot Bekas-12M
A Molot Bekas-12M pump-action shotgun dubbed the "FSB Shotgun" appears in the game.
The MCS version of the Remington 870 in Masterkey configuration is available as a front mount attachment. In game it is known as the "870 MCS Master Key." Unlike the first game, this one is shown correctly as having a 4 shell capacity with pump action reloading. A great add-on to your weapon.
The AA-12 is available for purchase. The 20-round drum is available for purchase later. As you would expect, firing off only a couple shells will lead to the Aggro meter skyrocketing to one side.
A hybrid M249 SAW is available for purchase. The stock gun comes with the fixed stock of a full-sized M249, but with the short barrel of a M249 Para, as well as the ammo bag of a M249 Para. The M249 E1 barrel, 120-round ammo box, and Para telescoping stock are available upgrades.
The General Dynamics GAU-19/A is used by the FDI machine gun heavy. Once the heavy is defeated, the player can pick it up however, the few times in the game in which this happens there are almost no enemies to use it on.
The RPG-7 is available for purchase. Like in the first game, there's no way to customize it other than paint scheme. Used extensively by FDI mercenaries.
The grenades available in-game, can also be customized to be diamond encrusted (whether or not this is cosmetic or changes damage is unknown)
M67 fragmentation grenade
Fan Designs
AS-KR1
The American winners of the Army of Two design contest created the AS-KR1. They were members of a website called The Angry Joe Show and call themselves the Angry Joe Army. Design was drawn up by internet artist Marobot.
Chambered in 7.62 X 39mm with enhanced accuracy due to the built in ranged scope. The weapon comes with an underslung shotgun that can chamber regular shotgun shells, airburst shells, and less lethal tazer shells (supposedly to imitate the webshow host's chain lightning ability).
The developers of Army of Two: The 40th Day held a gun design contest in which the winners will have their guns put into the game. One of the winners was the Grand Pinger, designed by members on an online image board called OPERATORchan. The rifle's name is derived from the M1 Garand and the distinctive sound that is made when a clip is ejected. The gun is a modified Mosin-Nagant with a shotgun stock, backwards mounted SVD magazine, EoTech along with a backwards mounted ACOG. It also features a backwards vertical grip, a paintball gun hopper, a backwards laser sight, a backwards flashlight, and a small suppressor. The final product, while retaining many features of the original, has been modified. It was entered as a joke, with a description describing it as "designed by Mack of FutureWeapons".