Across the years many alterations were made to her armament. The first change was to consolidate the 5-in gun battery by pairing the four main deck guns with the four gallery deck guns. The anti-aircraft armament received a major upgrade when six 1.1-in quadruple mounts were installed; the 1.1-in battery replaced a battery of 3-inch (76 mm)/50 caliber guns installed months before as placeholders. In March 1942, the .50 cal machine guns were exchanged for much more capable Oerlikon 20mm cannons. Similarly, the 1.1-in battery was swapped with quadruple Bofors 40mm guns in December 1942. "Ranger's" ultimate armament was six 40mm quadruple mounts and forty-six 20mm mounts.