384

Here you can see the packing tape at the forward end of receiver and magwell. I used a roll pin punch the same size as the holes in the magwell to mark the hole locations. This worked very well, If your not familiar with what that is, it is a punch that has half of a ball on the end, slightly smaller that the diameter of the punch. The ball made a very light mark of where center of the hole is and made center punching the spot for drilling much easier. I then removed the alignment rod and magwell, punched and drilled the 3 holes with the #36 drill bit, and taped with the 6/32. Be sure to use tap cutting lubricant and work in short movements of the tap reversing direction often to clear the newly cut threads! Other wise you might break the tap off in the receiver