Grumman F4F Wildcat airplane model. By the end of 1941 the Grumman F4F-3 (and similar F4F-3A) fighters, which had received the popular name "Wildcat" a few months earlier, had replaced the F2A in most U.S. Navy and Marine Corps fighting squadrons. A folding-wing version flew in April 1941 and entered service in early 1942 as the F4F-4. Prompted by British tactical concepts, it had six guns but less ammunition. The heavier F4F-4 was not as nimble nor as fast as the F4F-3, but the logic of wartime manufacturing left it as the sole remaining production version, and its folding wings made it possible to cram more valuable fighters into each aircraft carrier. By the Battle of Midway in June 1942, all the Pacific Fleet's carriers had the F4F-4 and fighting squadron pilots were learning, sometimes painfully, how to best employ it. Employ it they did, quite successfully, through the Pacific's intense Guadalcanal and Central Solomons campaigns and the Atlantic's North African operation. In late 1942 and early 1943, Grumman phased out production of the F4F-4 and General Motors' Eastern Aircraft Division took it up as the FM-1 (with two less guns). In all, the two companies produced some three-thousand "Wildcats" for the U.S. and Britain before GM's factories switched to the updated FM-2 in the later part of 1943.