[youtube]http://www.youtube.com/watch?v=cxwPEL8winI[/youtube]
http://www.youtube.com/watch?v=cxwPEL8winIThis guy made a pretty detailed animation of how burst mode works in a M16A2 or M4. On the way he also explains semi and full auto work in a M16A1 or M4A1 so you can see how the auto sear works. His youtube channel is kind of weird but there are a few videos like this in it. I found it while surfing gun channels adn thought it was cool so I thought I'd share. Enjoy!