The above video shows technicians loading an F-15 with what they say are a thousand rounds of 20mm ammo. (wikipedia.org reports that the F-15 Eagle maxes-out at 940 rounds.) In contrast, the Air Force’s new F-35A will be equipped with a four-barrel GAU-22/A gun limited to 182 rounds of 20mm.
The most ammo-heavy variant of the new F-35 — the Navy’s F-35C aircraft carrier version — will hold 220 rounds of 20mm. And while we’re at it, the A10 Warthog’s seven-barrel 30mm GAU-8/A Avenger gun can pack as many as 1,174 rounds, firing at a fixed rate of 3,900 rounds per minute.
Meanwhile, the Marines are talking up their desire to put a laser weapon on the F-35. You know; someday. Make of that what you will.