43rd and 52nd Regiments take over the attack role, while the 315th remained in its defensive perimeter southeast of Base 82. The infantry battalions would move into the rubber plantation and attack from the north. General Thuần agreed and left for Joint General Staff headquarters to ask for a new ammunition allocation for the attack. He returned to his headquarters in ill-humor, for General Đổng Văn Khuyên, the Chief of Logistics, was unable to satisfy this request. By 15 June, the two leading 43rd Infantry battalions, one of which was attempting to swing north of Base 82 from An Dien, had made very little headway against strong resistance and heavy PAVN artillery fire. In contacts south of Route 7 on the 17th, prisoners were taken from the 272nd Regiment, soldiers who had recently arrived in South Vietnam and had been assigned to the 272nd for only three days before their capture. ARVN casualties continued to mount, troops were desperately fatigued, artillery support was too severely rationed, and the weather all but eliminated effective air support. On 21 June, General Thuần ordered a halt in the attempt to take Base 82, while a new approach, better supported by artillery fire, could be devised. Consideration was also given to replacing the 18th Division, whose troops had been in heavy combat for a month, with the 5th Division. Instead of relieving the 18th, General Thuần decided to try his armor again. Holding the infantry in position, he sent the 318th and 322nd Task Forces back into the Triangle, one north of Route 7, the other generally along the road. The PAVN's antitank defenses, primarily employing the 82-mm. recoilless gun, stopped the attack once again, destroying 13 M113 armored personnel carriers and 11 M48 tanks between 27 June and 1 July, even though ARVN artillery and the RVNAF supported the attack with 43,000 rounds and 250 sorties. The tired infantrymen of the 43rd Regiment tried once again to take Base 82 from the south on 1 July but got nowhere. On 2 July, General Thuần finally decided to relieve the 18th Division and replace it with the 5th. The armored task forces would be withdrawn for rest and refitting. General Thuần allowed his commanders ten days to complete the relief. In order not to weaken the 5th Division's defenses north of Lai Khê, elements of the 18th Division's 52nd Regiment, which had seen little