Lower Receiver Parts Kit – M16 w/ Auto Sear and Pin


Lower Receiver Parts Kit – M16 + Auto Sear and Pin

No MIM here. Luth-AR produces only the best quality, American made parts for the AR platform. All of the parts included in our lower parts kits are investment cast or otherwise machined to Mil-Spec drawings, materials and heat treat. Springs are a combination of 17-4 SST and various Mil-Spec steel wire are used in all of our springs with certification.

Disclaimer: The M16 Auto Sear kit is subject to NFA rules and is intended to be installed by a qualified gunsmith in a legally owned NFA firearm. This is not a kit that will convert a normal AR15 into an automatic firearm. Such modifications constitute violations of Federal firearms laws.

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Lower Receiver Parts Kit – M16 + Auto Sear and Pin

All NFA Rules Apply


  • LR-01 Buffer Retainer 1-ea.
  • LR-02 Buffer Retainer Spring 1-ea.
  • LR-03 Trigger Guard 1-ea.
  • LR-04 Trigger Guard Pin 1-ea.
  • LR-08A Auto Selector/Safety 1-ea.
  • LR-09 Bolt Catch Spring 1-ea.
  • LR-10 Bolt Catch Buffer (Plunger) 1-ea.
  • LR-11 Bolt Catch 1-ea.
  • LR-12 Bolt Catch Roll Pin 1-ea.
  • LR-13 Magazine catch 1-ea.
  • LR-14 Detent Spring 2-ea.
  • LR-15 Takedown Detent 2-ea.
  • LR-16 Mag Catch/Buttstock Plunger Spring 1-ea.
  • LR-17 Magazine Catch Button, Aluminum 1-ea.
  • LR-18 Front Pivot Pin 1-ea.
  • LR-19A Auto Disconnector, AR16 1-ea.
  • LR-21 Auto Trigger AR16 1-ea.
  • LR-22 Trigger Spring 1-ea.
  • LR-23 Pistol Grip Bolt 1-ea.
  • LR-24 Pistol Grip Lock Washer 1-ea.
  • LR-25 A2 Pistol Grip, Black Plastic 1-ea.
  • LR-26 Selector/Ejector Spring 1-ea.
  • LR-27 Detent (Selector) 1-ea.
  • LR-28 Hammer/Trigger pin 2-ea.
  • LR-30 Pin, Rear Takedown 1-ea.
  • LR-31 Disconnector Spring 1-ea.
  • LR-32 Hammer Spring 1-ea.
  • LR-34K Hammer AR16, Mil-Spec w/J Spring 1-ea.
  • LR-AS1 Auto Sear W/Spg M16
  • LR-AS2 Auto Sear Pin M16



Additional information




.223 / 5.56


Manganese Phosphate

Manufacture Method


UPC Code