The external ballistics software program by JBM Ballistics predicts that the bullets of British high pressure .338 Lapua Magnum cartridges using 16.2 g (250 gr) Lapua LockBase B408 bullets fired at muzzle velocity under International Standard Atmosphere conditions at elevation assuming shooting and target positions are at equal elevation and a zero (the distance at which the rifle is sighted in) arrive at distance after approximately 6.017 seconds flight time at velocity and have dropped (in angular units 48.9 milliradian , 168 MOA) on their way. Harrison had to use the P4 reticle offering 0.5 mil spaced holdover hash marks in his 5-25×56 telescopic sight to compensate for the lack of vertical aiming correction and thus achieve the required aiming solution. The long horizontal line at 5× zoom or magnification represent 49.1 milliradian (168.6 MOA) or slightly over the required assumed vertical elevation.