While the 60mm and 82mm mortars were scattered around in proximity of the combat base (roughly within a 2,000-3,000 meter radius), the NVA rocket sites and artillery pieces were located well to the west, southwest, and northwest, outside of friendly counterbattery range. One particularly awesome and effective weapon was the Soviet-built 122mm rocket, the ballistic characteristics of which had a lot to do with the way the North Vietnamese employed it. When fired, the projectile was fairly accurate in deflection but, because it was powered by a propellant, the biggest margin of error was in range. Consequently, the North Vietnamese preferred to position their launching sites so the gunners could track along the long axis of a given target; thus, longs and shorts would land "in the ballpark." The KSCB hugged the airstrip and was roughly in the shape of a rectangle with the long axis running east and west. This made the optimum firing positions for the 122mm rocket either to the east or west of the base on line with the runway. There was really only one logical choice because the eastern site would have placed the rockets within range of the Americans' 175s and extended the enemy's supply lines from Laos. To the west, Hills 881S or 861 would have been ideal locations because in clear weather those vantage points provided an excellent view of Khe Sanh and were almost directly on line with the airstrip. Unfortunately for the NVA, the Marines had squatters' rights on those pieces of real estate and were rather hostile to claim jumpers. As an alternative, the North Vietnamese decided on 881N but this choice had one drawback since the line of sight between that northern peak and the combat base was masked by the top of Hill 861. Nevertheless, the enemy emplaced hundreds of launching sites along its slopes and throughout the siege approximately 5,000 122mm rockets rained on Khe Sanh from 881N.(84)