In today's post, we will look at a couple of videos that show the actual parts, instead of a 3-D Solidworks animation.
First up, an explanation of the AR-15 trigger mechanism:
Next, we have another video, that discusses the trigger mechanism of a M16 and compares it to that of an AR-15
Note that the M16 trigger mechanism being discussed is the M16-A1 model, which is capable of firing in semi-auto (single shot) and full-auto modes (unlike the M16-A2 and A4 models, which can fire in semi-auto and 3-round burst modes only). The AR-15 is capable of semi-auto fire only.