Finish your AR15 lower with this comprehensive Mil-Spec Lower Parts Kit. Includes every pin, spring, detent, and component needed for a fully functional lower—minus buffer tube assembly and stock. The phosphate-coated single-stage trigger delivers crisp, reliable 5.5–7 lb pull with proven mil-spec geometry. All parts are precision-machined for drop-in compatibility with any Mil-Spec AR15 lower receiver. Single-stage Mil-Spec trigger, trigger spring, hammer, hammer spring, disconnector, disconnector spring, trigger pin, hammer pin, selector, selector detent, selector detent spring, bolt catch, bolt catch plunger, bolt catch spring, bolt catch roll pin, magazine catch, magazine catch button, magazine catch spring, takedown pin, pivot pin, takedown/pivot detents (2), takedown/pivot detent springs (2), buffer retainer, buffer retainer spring, trigger guard, trigger guard roll pin, bolt release roll pin, A2-style pistol grip, pistol grip screw, pistol grip lock washer.

Every One Horse rifle and component is made in America with uncompromising standards. We use U.S.-sourced materials, U.S. manufacturing, and strict quality control at every step. No shortcuts, no imported surprises — just dependable parts built by people who take pride in American craftsmanship. When you run One Horse, you’re running gear you can trust every single day.