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Perhaps the three best-known sniper rifles in current service are the US Army's M24, the U.S. Marine Corps' M40 and the British Accuracy International L96 and AW. The M24 and M40 are precision rifles built based upon the civilian Remington 700 bolt action rifle, the best selling bolt-action in North America and dating back to 1962. The British L96 / AW was designed by Malcolm Cooper, a British civilian Olympic shootist.
Semi-automatic sniper rifles are currently less common than bolt-action rifles, with the notable exception of the Russian Dragunov in 7.62x54 (the old Soviet rimmed battle rifle cartridge originally chambered in the Mosin-Nagant). The Dragunov is relatively common in the sphere of influence of the former Eastern Block. The Dragunov in 7.62x54 is not as precise as the M21, M40 or AW series. A precision semi-automatic rifle is expensive and most sniping doctrines make the semi-automatic function superfluous. Precision semi-automatic sniper rifles exist for specialised applications, such as the Heckler and Koch PSG1 and Knight Armaments SR25M.
Most sniper rifles have heavy barrels to increase the resonant frequency (again) and slow the rate of heating, which reduces thermal distortion of the barrel as more rounds are shot. This is why the M24 Bolt-Action Sniper Rifle is actually heavier than the older M21 Semiautomatic Sniper Rifle.
The trigger sears may be polished so the trigger releases crisply. This reduces the shooter's tendency to jerk the trigger, and move the point of aim. A good trigger lets off or 'breaks' cleanly without any 'creep.' It is said to feel like snapping a glass rod.
A low-mass (often titanium) hammer and pin reduce the time between the trigger pull and the primer ignition. This reduces the distance that a human being's irreducible quiver can move the point of aim.
Military sniper rifles tend to have longer barrels of around 300 mm to allow the cartridge propellant to fully burn and get the fastest bullet velocity for a given charge. Some police sniper rifles have shorter barrels to make them easier to handle. The shorter ranges at which police operate permit lower bullet velocities.
Sniper rifles' sights are almost always telescopic. The reticle of the scope often contains markings other than the cross-hairs found in hunting rifle scopes. Some markings are to assist in range estimation by corresponding to standard objects at different ranges; other marks, such as mil-dots, assist both in "aiming off" for windage and in "holding off" to adjust for distance and elevation.
Sniper rifles' scopes rarely magnify more than 11x; the AW in British service has a fixed magnification of 10.5x. Modern sniper rifles often forgo open sights, relying entirely on the scope. Examples include the U.S. M21, M24, and M40. The British AW is still equipped with auxiliary open sights. Some scopes have fixed magnification as low as 3x. Police sniper rifles often have an adjustable zoom scope, as much police work is done at close range and a high magnification scope restricts the field of view.
Some sniper equipment includes an image intensifying adapter to convert the normal scope for night work.
A sandbag helps one to achieve the best accuracy, although these are typically only available in target shooting, police stand-offs, and base defense. In the field, a bipod is more common, although any soft surface such as a rucksack will work. Any of these will steady a rifle and help ensure consistency. In particular, they help one fire from a prone position, the most accurate position for firing a rifle. They also help one hold any firing position for an extended period of time. Many police and military sniper rifles come equipped with an adjustable bipod.
Since 1985, some services have adopted sniper rifles that fire rounds larger or more powerful than a standard battle rifle's. Such rifles are used for anti-materiel missions and for extreme long range. US doctrines call "anti-materiel" roles hard target interdiction. They are big, heavy, cumbersome, very loud and expensive. In many sniping missions these would be a disadvantage, but these big rifles do have their tactical niche.
Such rifles include the Barrett M82A1 chambered in the .50 BMG (Browning Machine Gun) cartridge. This cartridge generates about six times the energy of a 7.62 x 51 mm NATO cartridge. Splitting the difference between the huge .50 BMG and the 7.62 x 51 mm in the power stakes are the .338 Lapua and .408 Chey-Tac. A new Sniper rifle undergoing testing is the Barrett XM109 rifle, firing a high-explosive 25 mm round.
Most snipers are issued match-grade military ammunition. Ammunition with a boat-tail (narrowing at the base end) are often selected for long-range sniping.
Though target shooters often assemble their own ammunition from components to more precisely control the load and tune it to the specific rifle and task, this is practically unknown in military and police circles.
The basic camouflage item of a working sniper is a combination of cover and shelter, usually a poncho or shelter-half, preferably with attachable insulation and internal waterproofing.
Snipers against well-equipped forces must camouflage themselves in Infrared (or IR). They use material with a thin layer of evaporated aluminum to reflect the IR, such as plastic foil blankets. Originally these were thermal blankets, covered with local foliage or material. The foliage or material is taken from at least 275 m (300 yards) away so the sniping position's natural cover is
The best-equipped snipers use a Tick suit. This consists of IR-proof material that hangs in folds over the sniper, breaking up the outline on a scope. The outer layers of a tick suit resemble a ghillie suit, camouflaging the sniper in visible light.
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