Lower & Upper Receivers

The MR556A1 Upper Receiver Kit includes a complete upper receiver/barrel assembly, bolt carrier assembly, buffer, and buffer spring allowing most high-quality 5.56 mm AR-style rifles to be retrofitted to HK’s pusher rod system. The Upper Receiver...

Knights Armament SR-25 upper receiver kit, chambered for 7.62x51mm. Featuring Knight’s 20” cut rifled, precision barrel and their newly designed 3-prong QDC flash hider, the 20” Precision Rifle upper is the ultimate choice in the...

Built to the same standards as the complete SR-25 rifles, this lower receiver assembly features ambidextrous bolt, selector, and magazine releases, providing left-handed users with the advantages of AR-15 style controls, while offering right-handed users...

  The Knight's Armament SR-30 IWS Complete Lower Receiver comes with with a SopMod stock and ambidextrous controls.   Complete Lower SopMod Stock Ambidextrous Controls

The Knights Armament SR-15 E3 Mod 2 series' 5.56 mm NATO barrel is manufactured for military grade durability, and is free-floated inside a URX4 M-LOK handguard. An improved E3 round-lug bolt design both enhances function and increases bolt life far...

The Knights Armament SR-15 E3 Mod 2 series' 5.56 mm NATO barrel is manufactured for military grade durability, and is free-floated inside a URX4 M-LOK handguard. An improved E3 round-lug bolt design both enhances function and increases bolt life far...

The FN SCAR(R) barrel assemblies are cold hammer-forged, chrome-lined MIL-SPEC steel barrels with front sight assembly, gas block assembly, gas regulator, gas piston and flash hider installed. Available in short lengths for reduced weight, fast handling...

The FN SCAR(R) barrel assemblies are cold hammer-forged, chrome-lined MIL-SPEC steel barrels with front sight assembly, gas block assembly, gas regulator, gas piston and flash hider installed. Available in short lengths for reduced weight, fast handling...

The LMT Modular Ambidextrous Rifle System (MARS) lower receiver offers ambidextrous controls to include the selector, magazine release and bolt catch and release. The ambidextrous magazine and bolt catch mechanisms are machined directly into the receiver...

The LMT Defense MARS-L DMR Complete AR15 Lower Receiver (M7DM4) is purpose-built for designated marksman rifle (DMR) configurations. The LMT® Modular Ambidextrous Rifle System (MARS®) lower receiver sets a new standard for ambidextrous AR-15 controls...

The LMT Defense MARS-L PDW Complete AR15 Lower Receiver (M7DA4SH) is a fully assembled, ready-to-build lower receiver featuring LMT's legendary MARS® ambidextrous control system. The LMT® Modular Ambidextrous Rifle System (MARS®) lower receiver sets a...

This stripped AR-15 lower is forged from highly durable 7075 aluminum and has a hardcoat anodized finish. It is fully compatible with Mil-Spec lower parts and made to the exacting tolerances LMT is known for. Forged 7075 aluminum Hardcoat...