Returning to the gunline off Vietnam on 6 November, the destroyer spent two weeks in Operation Traffic Cop, shelling the junks that were bringing arms and supplies to the Viet Cong. Within a fortnight, "Hamner" had destroyed 67 craft. On 14 November and 19 November shore batteries fired on "Hamner", and . Although several rounds sprayed the destroyers with shrapnel, neither ship was damaged. On each occasion the American ships moved outside range of the enemy guns and bombarded the shore batteries. Leaving the gunline on 20 November, a month and a day later, "Hamner" reached San Diego.