Semi-auto lower receiver is machined from a 7075 T6 aluminum forging to mil-spec dimensions for precise fit and outstanding performance. Ruggedized hardcoat anodized finish resists scuffs, scratches, and wear. Stamped and color-coded bullet selector position markings notify operator when weapon is in “safe” or “semi-auto.” A “full-auto” position is not selectable but gives this semi-auto lower receiver the appearance of being multi-burst capable. Magazine well features Spike’s spider logo and multi-cal engraving.

Note: Complete Lower w/Buttstock includes stainless steel trigger, black oxide finished trigger guard and hammer assembly, pistol grip, six-position mil-spec buffer tube (1.146" O.D.), ST-T2 tungsten heavy buffer, mil-spec 17-4 stainless steel buffer spring, and Spike’s M4 stock.

Note: Complete Lower without buttstock includes stainless steel trigger, black oxide finished trigger guard and hammer assembly, pistol grip, six-position mil-spec buffer tube (1.146" O.D.), ST-T2 tungsten heavy buffer, and mil-spec 17-4 stainless steel buffer spring.

SPECS: Receiver - 7075 T6 aluminum, hardcoat anodized, matte black finish. Buttstock – Reinforced molded polymer, black. “Cal Multi” stamped on side of magazine well. .154" hammer/trigger pin holes. .250" takedown/pivot pin holes.