There is a reason the military used full auto machine guns instead of single shot semi-autos (pull the trigger it fires a single shot) to bring down airplanes in WWII.
I recently read that during WWII Americans fired 12,000 rounds for every downed aircraft, and that German records closely paralleled those findings.
Granted these were military aircraft, but they were also using full auto machine guns to try to bring them down.
I guess that liberals extrapolating Kerry's service record would figure a box of .50 caliber in solider Kerry's hands would be the end of a whole bomber attack group.
And generally more than one at a time. Although bombers did use singly mounted .50s, most of the kills were by fighters which mounted from 4 to 8 of the big 50s, all firing simultaneously.
Ground troops, or sailors on ships, were very, very rarely able to bring down aircraft, even with quad (4) fifties. .50 caliber machine guns are no longer used in the air to air role, having been replaces by 20mm Gatling type cannons firing explosive rounds with proximity fuses.