Ultimately, the Marine Corps determined that the 37 mm guns of the M2s and M3s were not powerful enough to defeat Japanese bunkers, and so they would be replaced with tanks armed with 75 mm guns. Following the end of the Guadalcanal campaign, A Company returned to Australia, where the M2A4s were replaced with the new M4 Shermans in preparation for the Battle of Cape Gloucester in December 1943. They remained in service in some areas of the Pacific Theater until 1943. After they served in the Pacific, they were used for training.