A Sniper Rifle is a type of firearm featured in the Call of Duty series designed for long-range shooting. Sniper Rifles excel at long range, where the high power, accuracy, and zoom (given by the attached scope) allow players to kill enemies at ranges other weapons would be unable to do. However, Sniper Rifles do not perform well at close range, as they have very low hipfire accuracy and have long ADS times.
Sniper Rifles come in bolt-action and semi-automatic fire-modes. Bolt-action Sniper Rifles have high power, allowing for one-shot kills. However, these Sniper Rifles have high recoil and a low rate of fire, due to cycling the bolt between each shot.
Semi-automatic Sniper Rifles are much more diverse than bolt-action. The semi-automatic Sniper Rifles can have high power and recoil, or low power and recoil, allowing for follow-up shots if the first did not kill. Semi-automatic Sniper Rifles can be fired as fast as the user can shoot (aside from Black Ops, as all semi-automatic sniper rifles have a firecap, and the AS50 in Modern Warfare 3), unlike bolt-action Sniper Rifles.
Sniping in Modern Warfare 3 has been changed drastically. Instead of the base damage being 70 for all the sniper rifles, it has been raised to 98 (with the exception of the Dragunov and the RSASS, which are still 70). The damage multipliers for all the sniper rifles are the same, providing the same effect as previous games where some rifles would result in one shot kills from the stomach up and others would only be from the neck and head. In addition, going prone with a sniper rifle in Modern Warfare 3 has a massive benefit of reducing recoil to almost negligent amounts, allowing for rapid follow-up shots on any rifle, even the Barrett .50cal.