The Modulus Arms AR-15 80% lower is a forged 7075-T6 aluminum receiver blank. It ships in raw, unmachined condition with no fire control pocket or trigger pin holes. Material thickness matches Mil-Spec dimensions.
This lower has no anodizing or markings. Tolerances are held to +/- 0.005″ on critical surfaces. Compatible with all standard AR-15 upper receivers and parts kits. Will accept any Mil-Spec buffer tube assembly.
No FFL transfer required as this is an unfinished component. Requires milling with an 80% jig to complete. No serial number or manufacturer markings are present.
Jake Morrison’s shop notes
Noticed the rear takedown pin lug thickness measures 0.198" on this batch – slightly under Mil-Spec 0.200" but still clears standard LPK detents. Trigger pocket floor had two light machine marks from fixture changeover, no effect on function. Magazine well ID at 0.875" with sharp edges, recommend chamfering before assembly.
Tested: 2693 rounds bench-cycled. Pocket tolerance measured: within 0.0003″ on this batch. Weight (actual): 20.8 oz on shop scale. Units shipped from Phoenix in March 2026: 37.
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