My son purchased a bump fire stock for his AK47 and I supplied the ammo for the first outing with it. Wow, is it fun! What a great way to get close to full auto without paying a small fortune for it.
I was impressed at how easy it was to operate the stock. It was interesting however to notice when I got super high rates of speed, the trigger did not reset a few times and I had to eject the round in the chamber and keep going. But, wow, I got that thing really rocking!
Here's the video. The stock is a Slidefire: