Grip

Call of Duty 4: Modern Warfare
The foregrip is an attachment to weapons in Call of Duty 4: Modern Warfare that will reduce weapon recoil. The foregrip attachment is available for light machine guns and shotguns. It is unlocked when a player achieves 75 kills with a light machine gun, and 50 kills with a shotgun. Using the foregrip attachment will replace a player's tier one perk.

Call of Duty: World at War
The grip attachment is only available for the two shotguns, the Double-Barreled Shotgun and Trenchgun. It decreases weapon recoil just as in Call of Duty 4: Modern Warfare, and as previously, replaces the player's tier one perk. Instead of the polycarbonate synthetic pistolgrip from Modern Warfare, foregrips are basically wooden handles, finished and fashioned into sticks that simply attach to the gun's gripping area. With this attachment, the Double-Barreled Shotgun has a small wood handguard under the barrels rather than a vertical grip.

Call of Duty: Modern Warfare 2
The foregrip attachment is available for a number of weapons in multiplayer. It is usually one of the first attachments unlocked for a weapon by completing the weapons 'Marksman' challenges, except for shotguns, it usually takes 75 kills for them (Or Marksman III). Also, it no longer replaces the tier one perk.

Trivia

 * In Call of Duty: World at War, a Sawed-Off Double-Barreled Shotgun w/Grip is located just before entering the Asylum in the mission Ring of Steel, and in the Nazi Zombies game modes from the random weapon box. The shotgun is unique in that it combines two attachments on one weapon, something generally not possible in the rest of the game.


 * In Call of Duty 4: Modern Warfare and Call of Duty: World at War, some players consider the grip a waste of a Tier One perk, however, a possible way around the problem is to use Overkill with a gun that also has an attachment replacing the Tier One perk (Grenade Launcher/Rifle Grenade, or another weapon with a grip).


 * In Call of Duty 4, the M4A1 Carbine can usually be found with a foregrip (unless the M203 is attached), but it is purely cosmetic.


 * Some weapons automatically come with a non-functioning foregrip in Modern Warfare 2, as well. The MP5k and TMP are two examples of this.
 * In Modern Warfare 2, the grip is the only Marksman unlocked attachment that doesn't have an attachment unlocked by getting a certain number of kills with it attached.