The Evolution Of The Rifle

In recent decades, large-caliber anti-materiel rifles, typically firing 12.7 mm and 20 mm caliber cartridges, have been developed. The US Barrett M82A1 is probably the best-known such rifle. These weapons are typically used to strike critical, vulnerable targets such as computerized command and control vehicles, radio trucks, radar antennae, vehicle engine blocks and the jet engines of enemy aircraft. Anti-materiel rifles can be used against human targets, but the much higher weight of rifle and ammunition, and the massive recoil and muzzle blast, usually make them less than practical for such use. The Barrett M82 is credited with a maximum effective range of 1,800 m (1.1 mi); and it was with a .50BMG caliber McMillan TAC-50 rifle that Canadian Master Corporal Rob Furlong made the longest recorded (until 2010) confirmed sniper kill in history, when he shot a Taliban fighter at a range of 2,430 m (1.51 mi) in Afghanistan during Operation Anaconda in 2002.
Since then a British Army sniper beat the Canadian's record by 150 ft (46 m), by killing two Taliban insurgents at a range of 8,120 ft (2,470 m). He was using a standard issue British Army sniper rifle, the L115A3.
• Bullet Rotational Speed (RPM)
Bullets leaving a rifled barrel can spin at over 100,000 revolutions per minute (rpm) depending on the muzzle velocity of the bullet and the pitch of the rifling. The rotational speed of the bullet can be calculated by using the formula. The formula divides the number of inches in a foot (12) by the rate of twist that the barrel has. This number is multiplied by the muzzle velocity (MV) and the number of seconds in a minute (60). For example, a bullet with a muzzle velocity of 3,000 feet per second (910 m/s) leaving a barrel that twists once per foot (1/12") would rotate at 180,000rpm.