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A render of a bare aluminium AR-10 lower receiver seen from above at an angle: the open magazine well at the front, the trigger pocket in the middle and a round threaded ring at the back

Machined part designSolo, design and CADDrawing 33 of 33

LR-308
lower receiver

An AR-10 lower receiver I designed myself, to the DPMS LR-308 pattern. It's drawn to be machined from a solid 6061-T6 aluminium billet on my own CNC machine, and it isn't cut yet.

Sheet 02 of 04/The part

A lower cut from solid

The lower receiver is the frame the rest of an AR-10 rifle attaches to. This one follows the DPMS LR-308 pattern, the common AR-10 standard for .308.

The whole part is one solid body, so it can be cut from a single block.

A grey CAD-style view of the lower receiver model with black edge lines, seen from the top front corner
PL 04The model with its edges drawn, from the top front corner.
A grey CAD-style view of the lower receiver model with black edge lines, seen from the rear three-quarter with the threaded ring nearest
PL 05The model with its edges drawn, from behind and above, looking into the buffer-tube ring.

Sheet 03 of 04/Material

6061-T6, subtractive

It's drawn in 6061-T6 aluminium, and the plan is subtractive: cut from a solid billet, not printed or cast. 6061-T6 machines cleanly and takes anodizing well. At 2.70 g/cm³ the model comes out at about 350 g.

It will be cut on my CNC machine, once that is built.

A render of the aluminium lower receiver from behind and above, with the round threaded buffer-tube ring nearest the camera
PL 03A three-quarter view from the rear and above, looking into the threaded buffer-tube ring.
A grey CAD-style view of the lower receiver model with black edge lines, seen from below and to the side
PL 06The model from below, showing the magazine well and trigger pocket openings.
A side-on render of the aluminium lower receiver: a long body with the magazine well on the left, a rectangular trigger guard opening below the middle and a round ring rising at the right end

Sheet 04 of 04/Status

What this is not yet

It's a model and renders, not a part. Nothing has been cut yet, and the part waits on the CNC machine.

Only pictures are on this page. The model files and a dimensioned drawing are not published, because of federal firearms law and ghost gun file distribution laws.

PL 02The side profile, rendered in Fusion 360: the magazine well at the front, the trigger guard opening in the middle and the buffer-tube ring standing up at the back.