If you're trying to make your shooter game realistic, then you might want to know this:
An AK-47 is *not* a machine gun. It's considered an "infantry assault weapon". A real, military grade AK-47 has only two modes of firing:
1) semi-auto (fires one shot per trigger pull)
2) full-auto (fires bullets until trigger is released or magazine is empty)
AK-47s don't fire "bursts" of rounds with a single trigger pull. On full-auto, they fire at a rate of about 600rpm (rounds per minute).
Trust me, I'm one of those crazy American gun collectors!

But if you aren't trying to make a very realistic game, then don't worry about this. I just love realistic games, heheh.