THE ♥♥♥♥♥♥♥♥♥♥♥♥♥ AWP RANDS

The main purpose of the sniper rifle is to destroy valuable targets at extended ranges with aimed fire, and with as few ammunition as possible. In most cases, "the target" means the human being (enemy soldier, armed criminal, terrorist, president etc.), and the "as few ammunition as possible" often means "one shot". The range for sniper fire may vary from 100 meters or even less in police/counter-terror scenarios, or up to 1 kilometer or more - in military or special operations scenarios.
Some sniper rifles, mostly - large caliber ones, used also as anti-material weapons, to destroy, or, more often, render unusable or unoperable, targets such as radar cabins, jeeps, parked aircrafts etc.
History of sharp-shooting traces its ancestry well back into XIX or even into XVIII centuries. Early sniper rifles were standart issue army rifles, selected for accuracy, or privately purchased commercial target or hunting rifles. During WW I and WW II both sides used a lot of general issue bolt action rifles (such a Russian/Soviet Mosin M1991/30, US M1903A4, British SMLE No.4(t), German G98k etc.) fitted with some kind of telescopic sight. Some of general issued semi-auto rifles also were used in sniper role, such as Soviet SVT-40 and US M1 Garand.

The practice of developing the military sniper rifles from standart issue firearms is still used in many countries. Ususally, manufacturer or special military unit select some rifles for their better-than-average accuracy, then adopt these rifles for sniper role (i.e. convert them from select-fire into semi-autos, add ajustable stocks, bipods, scope mounts etc.). Many of military sniper rifles, discontinued in service or currently in use, such as US M21, German G3-ZF and G3-SG/1, were made that way.
Some sniper weapons were made for marksmen use from the scratch, because the clients wanted some special characteristics, that were unavailable in any service or commercial weapons. One such example - Soviet SVD Dragunov rifle. It was designed on Soviet Army request as a lightweight, powerful and reliable semi-auto rifle, and remains in service for almost 40 years.
But wast majority of sniper rifles, especially - police ones, were designed on existing commercially available hunting or sporting rifles. The best examples - the US military sniper rifles M24 and M40, along with many custom police rifles, were (and still are) built on Remington 700 actions, available for general public in many hunting and target rifles. Famous SIG-Sauer sniper ifles also buil on their (SIG or Sauer) hunting rifles. Some sniper rifles, mostly also police ones, designed on target/sporting rifles. To name few: Blaser R93 Tactical (Germany), Sv-98 and MC-116 (Russia).
In general, all sniper rifles may be rougly separated into 3 major categories: Miltary sniper rifles, Police/Law Enforcement tactical/sniper rifles, and Special purpose sniper rifles