cc-settings-icon BUILD AT HOME
80% Arms sells AR-15 and .308 80% Lower Receivers, 80% Lower Jigs and other accessories which allow you to legally build a firearm at home in most states.
We utilize state of the art 5-axis CNC machines to mill all our .308 and AR-15 80 percent lower receivers to incredibly precise tolerances using premium billet aluminum.
We also offer our patented AR-15 and .308 Easy Jigs® which is the first 80% lower jig that makes it ridiculously easy for a non-machinist to finish their 80% lower in under 1 hour with no drill press required.
Products manufactured by 80% Arms carry a lifetime warranty against manufacturing defects. We will promptly replace or repair any product that we determine to be defective.

SMITH DEFENSE - AR 308 Mil-Spec Lower Parts Kit

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Looking for a .308 lower parts kit to help you build a custom AR-308 from the ground up? Get the Smith Defense Mil-Spec Lower Receiver Parts Kit! With Mil-spec dimensions and high-grade coating, you are assured a high-quality and correct component interface. Our AR-308 Parts Kit comes complete with an A2-style pistol grip and is 100% made in the USA.

Complete AR-308 Lower Parts Kit for AR-308 Builds

When you want to turn a stripped AR-308 lower receiver into a fully-functional lower for assembly to the .308 upper receiver, count on our .308 lower parts kit for all the internal parts you need to complete the custom build. The kit parts are designed to work together and will require minimal fitting on your part.

The Smith Defense AR-308 Lower Parts Kit Includes:

Mil-Spec Fire Control Group with Ground and Polished Sear Surfaces:

Trigger, Hammer, Disconnect, Trigger Roll Pin, Trigger Spring, Hammer Roll Pin, Hammer Spring, Disconnect Spring

AR-308 Pin Kit:

.308 Takedown Pin, .308 Pivot Pin, Takedown Pin Detent, Pivot Pin Detent, Takedown Detent Spring, Pivot Pin Detent Spring

Mil-Spec A2 Style Pistol Grip:

A2 Style Pistol Grip, Pistol Grip Lock Washer, Hex Pistol Grip Screw

AR-308 Bolt Catch:

.308 Bolt Catch, Bolt Catch Plunger, .308 Bolt Catch Screw, Bolt Catch Spring

Mil-Spec Magazine Catch:

Magazine Catch, Magazine Catch Button, Magazine Catch Spring

Mil-Spec Buffer Retainer Kit:

Buffer Retainer, Buffer Retainer Spring

Mil-Spec Selector Kit:

Safety Selector Detent Spring, Safety Selector, Safety Selector Detent

Whether you want to rebuild worn AR-308 80% lower internals of an old rifle or restore your AR-308 80% lower receiver to like-new reliability and function, be sure to order the Smith Defense AR 308 Lower Parts Kit through our online store.


**Please note that we recommend buying our Extended Mag Catch Button for .308 as it is not included in the kit. The button is a drop in replacement for the standard lower receiver magazine catch button. This extended button is longer, allowing it to protrude further used with our lower to make magazine release easier.