The M21 can be unlocked in Call of Duty 4 multiplayer at level 7. It is the second sniper rifle obtainable. The M21 is useful in many situations,as it has very low recoil and is. What it lacks in its damage, its higher capacity magazine and increased rate of fire make up for. It is the only sniper rifle that cannot kill in one shot with stopping power perk enabled and because it is semi automatic it is highly inaccurate when not holding breath. As with all sniper rifles, it can be customised with an ACOG scope.
In the game, the M249 SAW is one of the first available weapons when starting. It has a very high rate of fire which, when doubled with stopping power, can bring down enemies with a quick burst. It is one of the most commonly used weapons in the game.
The M4 Carbine is one of the starting weapons in the game. It is known commonly as a 'cousin' to the M16A4, because of its similar look, power and effectiveness. There is, however, one major difference. The Carbine is a fully automatic rifle, perfect for those who enjoy depressing the trigger for elongated periods of time.
In Call of Duty 4 multiplayer, the M40A3 is a commonly accepted by veteran snipers to be the best sniper because it has the best accuracy and its lower recoil than other bolt-action sniper rifles. With stopping power perk it can kill with one shot.
The M60 is unlocked at Gunnery Sergeant (lvl. 19). Attachments include the red dot sight the grip and the ACOG scope. The M60 is the strongest machine gun in Call of Duty 4 multiplayer, having the best accuracy and power, but with a large recoil. It, along side an RPG, have enough firepower to kill an enemy helicopter in multiplayer. It is often combined with the perks Double Tap to increase its fire rate and Deep impact to increase the bullet penetration especially over long distances, making it more devastating. This weapon can be customised with gold colour scheme.
Like all Light Machine Guns, it has a large magazine capacity of 100 rounds. But it also suffers from a slow reload time.
The MP5 is the only SMG available at level 1. However, many players of level 39 or lower use this weapon for its amazing accuracy. At level 40, SMG users generally switch to the P90. The MP5 can be equipped with a red-dot sight, silencer and ACOG scope. Most seasoned players consider this the best weapon for Search and Destroy, equipped with the silencer.
The accuracy of the MP-44 is higher than that of a submachine gun so that it could shoot targets at a much longer range than an average SMG can. The MP-44's rate of fire is quite high, allowing the gun to be used in close-quarter combat. The MP-44 also has a strong power so it is a dependable gun for any battle.
In multiplayer, the Mini UZI is an unlockable weapon that can be upgraded with a red dot sight, silencer and ACOG scope. The Mini-Uzi is one of the weapons that can be customised with golden coloured paint.
In Multiplayer, the P90 is unlocked at Colonel (Lvl 40). It is customizable with a red dot sight, ACOG scope and silencer. This is by far the most popular weapon, used by almost every single player who has unlocked it. It also boasts a tremendous 50 round magazine, although its high rate of fire will eat through ammo surprisingly fast. Many consider the P90 to be somewhat overpowered, a similar view to the M16A4.
In multiplayer, the RPD can be upgraded with a red dot sight, an ACOG scope and a grip. It is primarily used for medium to long distances and is particularly liked for its magazine's high capacity. It is also a weapon available at level 1.
the RPG is the 'rocket-launcher'. In Multiplayer, it can be used as a Perk 1, which will allow the player to spawn with 2 rockets. However, this perk cannot be accessed if a player's primary weapon has a grenade launcher or grip attachment.
The R700 is much like the M40A3, except it only holds four rounds, has increased damage, and has greater recoil. The R700's sway is set higher then all the other snipers, meaning that it will move more if breath isn't held.
The Skorpion is always your starting weapon when playing the Old School portion of multiplayer. Unless at very close range or achieving a head shot, the weapon is considered weak since an entire clip will not be enough to kill an opponent. Apart from Old School gameplay, the weapon can be devastating with appropriate perks and attachments such as stopping power and red dot sight.
The smoke grenade is perfect for obscuring an enemies view of a particular target. It is primarily used on a headquarters, Sabotage bomb or Search and Destroy bomb.
Stun grenades are used in multiplayer to temporarily disorient and enemy player. Players stunned by the grenade will be experience a few seconds of slow movement and a white screen. Players are easily killed while in a 'stunned' state.