Machining an AR15 lower receiver

[Highpower]

Drilling and reaming the hole for the selector (safety) lever, and milling the flats on the “stop” lugs to keep the lever from over-rotating. Here the lever is being checked for proper fit in the hole.


I guess I forgot about taking pics of a couple of steps, but here is a view after drilling and reaming the holes for the hammer and trigger pins / drilling holes for the bolt catch and magazine catch springs, and milling the necessary slots in the side to hold bolt and magazine catches themselves. Also the left side of the pistol grip tang has been milled to thickness.




Forging is flipped over and finding the edge to begin work on the right side.


Here the rear take-down pin hole has been counter sunk / the slot milled for the magazine release button / the detent spring housing milled for the front take-down pin head / the right side of the pistol grip lug milled to thickness / and finally… a bleed hole drilled into the detent spring housing. Whew!


This is where things started to get interesting. Standing the forging on end and trying to drill a tiny little hole (straight!) through these lugs which is extremely close to the side of the forging. A 13” aircraft drill is used to get the drill chuck out of the way of hitting the work.


I did a LOT of careful measuring to drill a hole through a short piece of ½” square steel stock. When butted up against the angle plate and the side of the forging, the hole was in just the right spot to guide the business end of the drill bit without wandering.


Boring out the rear lug for the receiver extension. (Buffer tube.)