How does burst fire work?

[FIVETWOSEVEN]

I've always wondered how it works exactly, what makes it stop after 3 rounds? does anyone have a link or be able to explain clearly how it works? detailed pictures are desired.

 

[Jorg Nysgerrig]

http://www.thehighroad.org/showthread.php?t=292104

And from that thread, this link pretty much sums it up:
http://www.ar15.com/content/guides/function/burst/

 

[danprkr]

Thanks for asking. I always wondered, but never knew.

 

[luigi]

that's kinda cool thanks for posting

 

[FIVETWOSEVEN]

thanks for the info

 

[mlaustin]

Thanks, i've always been curious too. Good to know.

 

[essayons21]

Many an M4 has had its barrel burned up by GIs and a little filing on the burst disconnector.