having dropped or 2.8° from the original bore line. Due to the extreme distances and travel time involved, even a light cross-breeze of would have diverted such shots off target, which would have required compensation. The calculation assumes a flat-fire scenario (a situation where the shooting and target positions are at equal elevation), using British military custom high-pressure .338 Lapua Magnum cartridges, loaded with 16.2 g (250 gr) Lapua LockBase B408 bullets, fired at 936 m/s (3,071 ft/s) muzzle velocity under the following on-site (average) atmospheric conditions: barometric pressure: at sea-level equivalent or on-site, humidity: 25.9%, and temperature: in the region for November 2009, resulting in an air density ρ = 1.0854 kg/m3 at the elevation of Musa Qala. Harrison mentions in reports that the environmental conditions were perfect for long range shooting, "... no wind, mild weather, clear visibility." In a BBC interview, Harrison reported it took about nine shots for him and his spotter to initially range the target successfully. Military history Before the development of rifling, firearms were smoothbore and inaccurate over long distance. Barrel rifling was invented at the end of the fifteenth century, but was only employed in large cannons. Over time, rifling, along with other gunnery advances, has increased the performance of modern firearms. 1701–1800 Early forms of sniping or marksmanship were used during the American Revolutionary War. For instance in 1777 at the Battles of Saratoga, the colonists hid in the trees and used early model rifles to shoot British officers. Most notably, Timothy Murphy shot and killed General Simon Fraser of Balnain on 7 October 1777 at a distance of about 400 yards. During the Battle of Brandywine, Capt. Patrick Ferguson had a tall, distinguished American officer in his rifle's iron sights. Ferguson did not take the shot, as the officer had his back to Ferguson; only later did Ferguson learn that George Washington had been on the battlefield that day. A special unit of marksmen was established during the Napoleonic Wars in the British Army. While most troops at that time used inaccurate smoothbore muskets, the British "Green Jackets" (named for their distinctive green uniforms) used the famous Baker rifle. Through the combination of a leather wad and tight grooves on the inside of the barrel (rifling), this weapon was far more accurate, though slower to load. These Riflemen were the elite of the British Army, and served at the forefront