I've researched these numbers for yrs and they do vary slightly but overall are close enuff for comparison.
The F6F shined the last two yrs of the war and racked up its impressive numbers mostly from the decks of our carrier fleet against a dwindling Japanese pilot pool..
Single theater of OPS,#1 would be the
F6F Hellcat, with 5,168 kills in the Pacific Theater of Operations. Next would be the P-51 Mustang with 4,950 kills in the European Theater of Operations.
For the entire war combined, in all theaters, it would be the P-51 Mustang with 5,954 kills in ETO, MTO, PTO, and CBI all combined, followed by the Hellcat with 5,168 in PTO and ETO.
These numbers come from a 1945-1946 report compiled by the US Navy for the Hellcat and the Air Force Historical Society for the P-51. The Hellcat and Mustang are neck in neck for the title.
#3 on the kill list goes to the P-38, with 3,785 in all Theaters of operation combined. The theater of operations with the most enemy aircraft shot down was the PTO, with 12,666 enemy aircraft shot down.
F4U numbers although impressive were only around 2150 plus or minus.
These totals also include non air to air engagements with bombers,float planes and static ground attack kills.
