There is an internal limiter that limits bursts to for exemple 80 or less rounds. The idea is to fire that burst as quick as possible to put the 80 rounds into the air simultaniously putting a chunk of lead into the air. A single round is not likely to cause much damage to a jet but 30 or 40 hitting in a cluster will shread stuff.
Imagine it like a shotgun. Altought you only have 5-8 shots when you hit something you take a chunk out of it.