P90

The P90 ("Project 90") is a series of Belgian-designed submachine guns, originally started in the 1980s. The P90 is chambered in 5.7x28mm. It is fed by a horizontal translucent 50-round magazine. The base of the magazine is toward the barrel. The cartridges are fed into a spiral feed ramp, where they are rotated 90 degrees into the chamber. This unique feeding design accommodates a 900 rounds per minute firing rate and makes the weapon very compact. Spent casings exit through the bottom of the weapon, allowing the weapon to be used ambidextrously.

In Game
Call of Duty 4 features the P90 TR, a triple-railed variant. In singleplayer, the P90 is a rare weapon used only occasionally by Russian Ultranationalists on the later levels of the game. It can be found in Heat, All Ghillied Up, and Mile High Club. Typically, the weapon is unsuppressed and uses iron sights. However, there is also a suppressed version using an M4A1 SOPMOD-type red dot sight instead of iron sights, called the "P90 SD" found in All Ghillied Up, specifically, on the body of the enemy soldier Cpt. MacMillan says "Oi, Susy!" to and majority of the rest of the Russian troops. But in a cruel twist, these are the last enemies you can engage at close range for the level, and in "One Shot, One kill" you start with an M21 and either an USP, G3, or AK-47.

In multiplayer, the P90 is unlocked at Level 40. It can be modified with a Red Dot Sight, ACOG Scope, or suppressor. The P90 has a 50 round magazine and a very high rate of fire. It is better than other SMGs at long range due to its low recoil and high rate of fire. In addition, it is also the slowest-killing SMG at extremely close range. At close range it kills slower than the Skorpion, kills slightly slower than the Mini-Uzi, and has much better hip accuracy than the AK-74u if the AK has a red dot sight or silencer. There is often much debate about the P90 and the MP5. The MP5 has higher damage in close quarters combat and less obstructive iron sights. The P90 has a higher rate of fire, a bigger magazine, less recoil, and does the same damage in medium and long range combat.

In the PC version, having a P90 as a player's primary weapon greatly increases their sprint time. This glitch used to exist on consoles but was fixed with a patch. Because of this, the P90 is the best weapon in the game in terms of mobility in the PC version.

Trivia

 * The P90 TR in-game uses the H&K Detachable Diopter Sights found on the H&K MP7A1 as its standard iron sights.
 * The in game model uses a strange way of holding the weapon, resting the front of the weapon in the character's palm instead of the normal way of putting the thumb through the weapon's frontal thumb hole. It also has a flashlight that is unused, and the magazine always looks full to the player, (much like the G36C) despite the actual ammunition levels.
 * It has been likened to the PPSh-41, as both guns have a large magazine capacity and devastatingly high rate of fire.
 * The animation of the P90 is inaccurate, as it shows the magazine being yanked out instead of taken out after pressing the magazine catch.
 * When the P90 has a custom camouflage on it (for example digital), the camo will not appear on the magazine when used with a red dot sight or an ACOG scope. However, the camo will appear on the magazine with a silencer.
 * Unusually, the 5.7x28mm bullet is designed to pierce some models of body armor, but the in game P90 has low penetration. It is likely because Infinity Ward wanted to balance the P90.