@FliegerFaustToP47
Where the shots in even burst, or where they just frequent?
In America a lot of people have auto-loaders. They load the next round immediately, but you you need to release the trigger and pull again for each bullet. This can actually increase ammo efficiency, and become more deadly by offering the user precise control over each round. There will be random intervals between the shots, but no manual charging/chamber required, so they can be rapid.
A militarized firing mechanism would fire either a uniform burst, or keep repeating until the mag is empty or the trigger is released. Rhythmic uniform intervals like a helicopter blade, better for armored foes, but less effective for spree killing i think.