I bought a bolt carrier group. I came with the firing pin. A firing pin will not be in a lower parts kit.
Here is the BCG I bought:
Bolt Carrier Groups : M16/4 Full-Auto BCG - No Hammer
The cow and Mooolon Labe in ancient Greek was the last part I engraved.
My wife really liked the engraving. Now I need to degrease and blast this and see how it looks.
Completed the engraving. Here is the first roll mark. This daisy had a lot of detail, and took a lot longer than I expected to finish to the depth I wanted.