The Colt Anaconda is only available in multiplayer. It is referred to as "Magnum", which is contradicted by the buying menu stating that it is chambered in .45 Long Colt.
Desert Eagle Mark XIX
The Desert Eagle Mark XIX appears in the game, referred to as "D-Eagle", and used by Zaleb Said and his guards in the Libyan missions. It is one of the most powerful handguns in the game.
Glock 17
The Glock 17 is the starting pistol in the Russian levels and comes with a suppressor; it is referred to as the "G-17 SD". It provides accurate but weak firepower.
Heckler & Koch Mk 23 Mod 0
The Heckler & Koch Mk 23 Mod 0 is referred in-game as the "Socom" and comes with a suppressor and a usable LAM unit. It provides suppressed but effective shots; it is used by David in the Libyan mission, and Anya holds one in the last cutscene of the game. In multiplayer, it is erroneously stated to be chambered in 9x19mm Parabellum.
Makarov PM
The Makarov PM is used by Russian guards, and also by Russian and Chinese scientists as a backup weapon. Despite firing the 9x18mm round, it is attributed with a higher damage than the Glock 17. Wu Xing uses a Makarov PM (presumably standing in for the Type 59 Chinese copy) in the intro cuscene of the "Secret Weapons Lab" mission, where it uses the Desert Eagle's firing sound, likely due to the more dramatic sound of the Desert Eagle.
Submachine Guns
Heckler & Koch MP5A3
The player starts the game with the Heckler & Koch MP5A3. It incorrectly offers a 3-round burst option, which would be the case for other variants like the MP5A5.
Heckler & Koch SMG II
The Heckler & Koch SMG II, a canceled MP5 program, is available in the game with its integrated suppressor. It is David Jones' secondary weapon in the missions set in China.
IMI Uzi
The IMI Uzi is used by Libyan guards. Dual-wielded Uzis can only be found in the multiplayer.
Ingram MAC-10
The Ingram MAC-10 is used by Russian guards. In multiplayer, the buying menu states that it is chambered in .45 ACP, which contradicts the 32-round magazine used in-game.
Norinco Type 64
The integrally suppressed Norinco Type 64 SMG is used by Chinese special forces.
Assault Rifles
Colt M16A2
The Colt M16A2 is a starting weapon in the Russian missions, equipped with an M203 grenade launcher. It is used by the IGI special forces in the last cutscene of the game. It incorrectly fires in fully-automatic mode (like an M16A3) instead of three-round burst.
Heckler & Koch G11 K2
The Heckler & Koch G11 K2 is used by General Wu Xing in the "Secret Weapons Lab" mission, and is available to the player afterwards. It only fires in fast 3-round burst mode, and it offers a scoped view.
Heckler & Koch G36E
The Heckler & Koch G36E is only used by David in the Libyan missions. It incorrectly offers a 3-round burst option; the optional burst setting on real G36 variants is 2-round burst, nevermind the fact that the in-game weapon is modeled with an S-E-F trigger group, which lacks the burst function.
Norinco Type 56-1
The Norinco Type 56-1 appears; like the Zastava M70B1 from the first game, it is wrongly referred to as an AK-47. It is used by Russian and Chinese guards and Libyan special forces. In multiplayer, it is incorrectly listed as being chambered in 5.45x39mm.
Steyr AUG A1
The Steyr AUG A1 is available at the start of the Chinese missions.
Shotguns
Benelli M4 Super 90
The Benelli M4 Super 90 appears under the U.S. nomenclature "M1014" (even though U.S. forces don't even appear in the game), and is used by Libyan and Chinese special forces.
The Pancor Jackhammer returns from the previous game, its appearance again being incorrect since the real Jackhammer never entered production. It can be found in the Libyan missions, and is also used by Priboi and Zaleb. Once again it has an erroneous cylinder capacity of 12 rounds instead of 10.
Sniper Rifles
Barrett M82A1
The Barrett M82A1 is used by Chinese special forces. A version with a thermal vision scope is also available as the "M82A1-T" in "The Ancient Temple" mission.
Heckler & Koch PSG-1
The Heckler & Koch PSG-1 is used by Libyan forces. A suppressed version is also available as the "PSG-1SD".
Hybrid SVD Dragunov / Romanian FPK/PSL
Like in the first game, the "SVD Dragunov" (as referred in the text when picking up the weapon) is a hybrid of the SVD Dragunov and the Romanian FPK / PSL.
Machine Guns
Browning M2HB
The Browning M2HB is available mounted on various platforms.
FN Minimi
The FN Minimi is used by Chinese guards, and can also be found in the Libyan mission. Like in the previous game, it is simply reloaded by changing the belt box without actually inserting the belt into the feed tray.
Launchers
M203
The M203 grenade launcher is attached to the M16A2. Contrary to most the rest of the returning weapons from the first Project IGI, in this game the M203 is reanimated to properly depict it as a single-shot, break-open weapon that must be reloaded after every shot, rather than some sort of shotgun pump attachment that launches grenades so long as the user has any on their person.
The RPG-7 is available in the game with a PGO-7 scope. It is first seen in the mission "Ambush", where David Jones takes one from a Russian convoy to destroy an APC. The RPG is also used by Libyan special forces and Chinese guards.
Grenades & Explosives
Stun Grenade
Stun grenades (referred to as Flashbangs in-game) are used by Russian, Libyan and Chinese special forces in singleplayer, but are only available to the player in multiplayer.
C4
C4 explosives are used during certain objectives of the game.
L2A2 Hand Grenade
The main type of grenade in the game is the L2A2 hand grenade, the British version of the American M26 hand grenade.