Algodoo

Very detailed explaination of m16 internal mechanism...but its difficult to understand how the "burst" mode works is it scripted or just mechanical?

purely mechanical. if you know how the M16 disconnector works, you already know how the burst mechanism works. It is simply the same type of disconnector with another "hook" on it that engages a notched wheel. that notched wheel has four shallow notches and two deep notches. it rotates with the hammer backwards and rotates 60 degrees every shot. because there are two shallow notches on one side and one deep notch following on the burst wheel, the burst hook of the burst disconnector rides along those notches on the wheel. there are two shallow notches, where the burst disconnector cannot rotate forward far enough to snag the disconnector shelf on the hammer (that hook in the middle of the hammer). However, on the third shot, the burst wheel's deep notch rotates into place to allow the burst hook to move forward far enough to catch the hammer.

If you want, I can make a scene specifically explaining the burst kit and how it functions

That would be great thanks!