The American Tactical (ATI) MilSport aluminum stripped lower receiver (part no. ATIS ATIGLOWMS) gives builders an affordable, precision-engineered foundation for a custom AR-15 build, chambered for the .223 Remington/5.56 NATO family. Sold stripped, it ships with no internal fire-control parts installed, so you choose the trigger, safety, and furniture yourself. ATI backs the MilSport line with its long-standing manufacturing experience, making it a straightforward, no-frills option for a first AR-15 build.

Key Specifications

• Built as a multi-caliber AR-15 lower, compatible with standard chamberings such as .223 Remington/5.56 NATO, .300 Blackout, and 6.8 SPC.
• Machined from 7075-T6 aluminum for a durable, lightweight receiver.
• Sold as a stripped lower receiver, so no internal fire-control parts are installed.
• Runs a semi-auto action, firing one round per trigger pull with standard AR-15 components.
• Finished in black hardcoat anodizing for wear and corrosion resistance.
• Includes a proprietary magazine catch assembly and ejector pre-installed at the factory.
• Compatible with standard mil-spec AR-15 upper receivers and parts kits for a custom build.
• Ships at a light 0.65-pound shipping weight, keeping freight costs low for a parts order.
• Packaged one per box for individual sale.

Frequently Asked Questions

Does this lower include a trigger or other internal parts? No, it ships stripped, so you supply the fire-control group, buffer tube, and grip of your choice.

What caliber is this lower built for? It is chambered for the .223 Remington/5.56 NATO family on the standard AR-15 platform.

Will standard AR-15 parts kits fit this receiver? Yes, it uses standard AR-15 dimensions, so mil-spec parts kits and furniture already on the market will fit.

Buy the ATI AR-15 MilSport Aluminum Stripped Lower Receiver

Order this ATI MilSport stripped lower receiver from our Lubbock, Texas gun shop for fast, insured shipping to your FFL, and start your custom AR-15 build on an affordable foundation. Browse our full selection of AR15 lower receivers for more build options.