At the risk of being labeled a tacticool dork, I wanted to share my experience with the Slidefire solutions bumpfire stock. When I'm at the range, I don't do mag dumps and typically I like to work on my precision shooting, but the ability to have a simulated full auto for the fraction of the price was too tempting. I had to buy one and try it. These vids are of a member of the other forum who wanted to try this stock. We met up and I let him use my lower. I'm a lefty, so this is the lefty version of the stock but it still worked pretty good for him. These were 30 round mags.
http://img96.imageshack.us/img96/3712/lq5.mp4
http://img15.imageshack.us/img15/5628/90ar.mp4
http://img96.imageshack.us/img96/3712/lq5.mp4
http://img15.imageshack.us/img15/5628/90ar.mp4