History

The AS50 is a .50 BMG sniper/anti-materiel rifle manufactured by British firearms producer Accuracy International. The AS50 enables operators to engage targets at very long range with high accuracy using explosive or incendiary ammunition. The AS50 employs a gas operated semi-automatic action and muzzle brake, allowing for lower recoil than the AW50 bolt action rifle and faster target acquisition. The rifle is highly transportable, ergonomic and lightweight. It can be disassembled in less than three minutes and serviced without tools.
 
The rifle has an accuracy of 1.5 MOA. The barrel is free floated. The two-part machined steel receiver features an integral accessory rail for the mounting of optical sights. Two additional rails are mounted on the sides of the short barrel shroud. An adjustable bipod and rear support leg/hand grip allow for stable shooting. This weapon can accurately engage targets at over a 1,500 metres (1,600 yd) distance.
 
The AS50 weighs 14.1 kilograms (31 lb) empty and holds five rounds of .50 BMG in a single stack removable box magazine.

Singleplayer/Spec-Ops

Multiplayer

The AS50 is unlocked at level 22 in Call of Duty: Modern Warfare 3's multiplayer. It has low recoil, high power (a one-shot kill to the head, neck, shoulders, chest and stomach), and a 5-round magazine.The AS50 has a unique scope that has zoom similar to that of an ACOG Scope, making the AS50 more suitable for use at closer ranges than other sniper rifles. The Variable Zoom can be very useful on the AS50, as it wil retain the close range zoom, but can be zoomed in for taking out players at longer ranges that otherwise the default scope would have trouble hitting.

Attachments

Attachments	Challenges	Icon
ACOG Scope	Get 20 kills while looking through a ACOG Scope attached to a Sniper Rifle.
Silencer	Get 15 kills with a Silencer attached to a Sniper Rifle.
Thermal	Get 40 kills while looking through a Thermal attached to a Sniper Rifle.
Extended Mags	Get 40 kills with Extended Mags attached to a Sniper Rifle.
Heartbeat Sensor	Get 40 kills with a Heartbeat Sensor attached to a Sniper Rifle.
Variable Zoom	Get 40 kills while looking through a Variable Zoom Scope attached to a Sniper Rifle.

Proficiencies

Proficiency	Description	Icon
Kick	Kick Reduces recoil by 20%, allowing for steadier full-auto and faster recovery from shots.
Impact	Impact grants maximized penetration for any weapon. This is especially powerful on Assault Rifles and SMGs, as LMGs already have strong penetration, and Sniper Rifles are difficult to use for intentional walling shots.
Attachment	Allows the use of 2 Attachments. It is a solid all-around Proficiency, useful in many situations. This Proficiency is also notably useful for stealth builds, as it allows you to use a Silencer alongside any other Attachment. The Attachment Proficiency is also helpful if you are still getting comfortable with iron sights, as it allows you to take and optical Attachment and a second utility Attachment.
Focus	Reduces visual recoil by 50% when you are hit. Focus is very effective for SMGs and Shotguns. It is also helpful for ARs, as it can keep your shots on target when you enter a heads-up one-on-one firefight.
Speed	Improves movement speed by 10%, or one step up on the mobility scale. Speed is an important upgrade for LMGs and Riots Shields. It is less critical for Sniper Rifles, excepting the Barret and AS50, which are heavier and slower than other Sniper Rifles.
Stability	Reduces idle sway by 25%. Consider this to be an 'automatic' Breath for long-range combat. It is most useful on LMGs, as they need the enhanced accuracy for long-range shots, though ARs also benefit from it.

Challenges