Originally Posted by
lysander
8620 - trigger, safety, bolt catch, pivot pin, take down pin,
8620 - magazine catch plate (MIM)
4620 or 8620 - hammer
4130, 4140, 4340 - buffer retainer
1065, 1070 - disconnect
1018 - magazine catch plate (bar), magazine catch shaft, detents
303 stainless - trigger guard plunger
One thing I find interesting about the M16/AR design is how 'traditional' it really is, as far as construction methods go. The number of metal stampings is very few, less than half a dozen. And, only five major parts are aluminum.