I can't swear to it but I believe that the receiver did have to be drilled and tapped. The front sight blade was filed off the post so the post is flat. The post was then slotted and a blade fitted to the slot. The post with the blade inserted was then drilled for a pin and the blade then pinned in place. The blade is then filled down to the correct height, shaped and the face of it is grooved and blackened. I polished the head of the pin so that it would show up better in the picture. There is not much room for the blade to extend forward of the sight post because of the cheep aluminum magazine band but extending it some toward the rear keeps it from looking too tall. It takes about as long to do as it does to type it up.
