Microgun Pod
An 88 by 10 inch (224 x 25 cm) 5.56mm Microgun Pod was also developed for external use on light aircraft and helicopters. The unit had an ammunition capacity of from 1,500 to 3,500 rounds and loaded weight of 186 to 300 pounds. The feed system was linkless, via a helical drum, with a nominal rate of fire of 6,000 rpm. However, adjustments to 1,000 or 10,000 rpm were possible, if desired. Power could be provided by a built-in battery pack, or from the aircraft itself.
Read more about this topic: XM214 Microgun