AA-12

The Military Police Systems AA-12 (Atchisson Auto Assault-12) is a select fire shotgun considered to be the first shotgun directly designed for military and law enforcement use. It fires at 350 RPM (400 RPM ingame), and accepts an 8 shell detachable box magazine, or a 20 or 32 shell drum.

Multiplayer
The AA-12 is unlocked at level 18 in Modern Warfare 2's Multiplayer.

The AA-12 is a unique shotgun, as it is fully automatic and utilizes a magazine. It has an 8-shell magazine capacity, which is doubled when the Extended Magazines attachment is used, which balances the weapon's power and speed. The AA-12 empties its magazine far more quickly (400 RPM in multiplayer) than it reloads as the magazine needs to fit onto the magazine support, and then slide up into the magazine well, though this is slightly offset when the Sleight of Hand Perk is utilized. Since it uses magazines rather than individual shells, it is the fastest empty loading shotgun in the game.

In multiplayer, the AA-12 has only one extra magazine, so it is wise to use it sparingly, unless Scavenger is used. It has moderate recoil unless firing full-auto, and very poor range, even when compared with other shotguns. This means that players using the weapon will have to get fairly close to enemies to use it effectively. However this trait makes it a highly useful weapon for clearing rooms, or areas full of enemies. Using Extended Mags will increase the capacity to 16 shells, allowing prolonged fire. Using Extended Mags in conjunction with Scavenger (as otherwise, with Extended Mags, you have no extra magazines) can make it a highly useful weapon, and has made some players use it as a "primary" weapon. Using a suppressor with this weapon makes it almost completely useless, as it shortens the range to roughly 5-10 yards, which means that the user must get incredibly close to enemies to actually be able to hit them. The AA-12 is very effective on sabotage or demolition matches as it can clear out a room with ease due to its rate of fire.

It is also notable that with the Grip attachment, the AA-12's switch time is noticeably quicker than without the grip. Though this can be remedied by double tapping the 'switch weapon' button (Triangle on PS3, Y on Xbox 360 and 1 or 2 [Default] on PC) quickly to make the switch time quicker.

Weapon Attachments

 * Red Dot Sight
 * Heartbeat Sensor
 * Suppressor
 * Grip
 * FMJ
 * Holographic Sight
 * Extended Magazines

Modern Warfare: Mobilized
The AA-12 appears as one of the two shotguns available in Modern Warfare: Mobilized, the other being the SPAS-12. Though the AA-12 seems similar to the AA-12 in Modern Warfare 2, there many differences between the two. First of all, the AA-12 is a frequent starting weapon in the later levels of campaign mode; is used in the U.S. Marine missions most frequently. It also comes with a 32-round drum magazine by default, much greater damage per shel, a greater one-shot kill range, near infinite pellet range, and a much lower and controllable rate of fire than the Modern Warfare 2 version.

Singleplayer
In single player, the AA-12 is a versatile weapon, having a near infinite range, high damage, and a large 32 shell drum magazine. The extremely high range allows the player to make a kill at any distance, though the pellets will spread apart as the distance between the player and the target increases, negating the one-shot kill effect and decreasing accuracy considerably. Combined with the high damage, large shell capacity and near infinite range, one can fire multiple shells to make a kill at long range if needed. As mentioned before, the AA-12 is found in the later levels of campaign mode as a starting weapon, more specifically, in the levels Training, Closing In, To the Rig, and Oil Rig Confrontation.

Mulitplayer
In multiplayer the AA-12 is the second weapon to be unlocked for the Coalition multiplayer faction, taking 150 kills with the Coalition faction to earn.

Call of Duty: Modern Warfare 2

 * The AA-12 fires faster, has better range, and lower recoil in singleplayer than in multiplayer.
 * The AA-12 has a different reload when the Heartbeat Sensor is equipped (only available in single player); the empty magazine will actually be thrown away when reloading, instead of disappearing off-screen as is the case with other attachments. The Heartbeat Sensor is also very visible even when aiming down the sight, a characteristic that is shared with multiple weapons including the TAR-21 and the L86 LSW.
 * In the Spec Ops mission, Acceptable Losses, players start off with the AA-12 with three different attachments, the Red Dot Sight, Silencer and a Heartbeat Sensor. This cannot be achieved in multiplayer.
 * The AA-12 Shotgun is the only weapon of its type that requires the player to pull a charging handle during an empty reload.

Modern Warfare: Mobilized

 * In Modern Warfare: Mobilized, the AA-12 has a Drum magazine. In the console version, it is not possible to equip the AA-12 with a drum magazine.

Video
thumb|left|300px|AA-12 Montage/Gameplay