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.

GST-9: MOD100

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Maximum Purchase:
1 unit
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For a limited time, get the Premium Smith Defense Lower Parts Kit pre-installed in your frame plus compact and full-size grips for free! This deal gives you $279.99 worth of value for only $159.99.

At 80 Percent Arms, we are excited to unveil the latest evolution in our lineup: the GST-9 MOD100 frame. This new offering brings our well-regarded GST-9 MOD1 into a realm of greater convenience and readiness by now arriving as a fully completed, ready-to-use firearm. 

All proceeds from the sale of the MOD100 will be directly used to fund the battle against the ATF to reinstate the manufacturing and sale of the 80% GST-9 frame. Your purchase helps support our fight for your firearm rights and preserve the greater DIY firearm building community.

The Smith Defense lower parts kit is specifically designed for the GST-9. It includes a wide-face billet aluminum trigger shoe, polished trigger bar, and upgraded connector for a smooth pull with a glass-like break. The kit also features an extended slide lock, slide stop, and magazine release for better ergonomics and easier manipulation of the controls during firing and reloads.

All parts are installed by a certified armorer and each frame is test fired. We offer a lifetime warranty on our products and are dedicated to your complete satisfaction.

Key Features:

Enhanced Modularity: The GST-9 MOD100 frame offers the flexibility of a 19, 19X, 19L, & 17 size weapon system in a versatile 4-in-1 platform.

Uncompromised Compatibility: Fully compatible with Glock 19 Gen 3 parts, holsters, and a wide array of aftermarket accessories.

Ergonomic Design: Features include an undercut trigger guard, high beavertail, glove bevel, scalloped mag release, and gas pedals for optimal support hand positioning.

Superior Internal Rails: Constructed from high-quality stainless steel, the internal rail components are extended to 3X OEM length for lasting durability and function.

Advanced Magwell Design: The built-in flared magwell aids in fast, smooth magazine changes, removing the need for external magwell additions.

Diverse Caliber Compatibility: Accommodates a range of builds including 9mm (G19), .40cal (G23), and .357 Sig (G32).

Ready for Immediate Use: Delivered fully assembled and ready for action, simplifying the ownership process from the start.

At 80 Percent Arms, our commitment to exceptional customer service and product quality remains unwavering. The GST-9 MOD100 is backed by a lifetime warranty*, guaranteeing your satisfaction and trust.

Compatibility Notes: The GST-9 MOD100 is fully compatible with Glock 19 Gen 1-3 internal parts and slides.

Regulatory Information:
As a fully completed firearm, the GST-9 MOD100 adheres to ATF regulations and requires shipment to a Federal Firearms License (FFL) holder. We are devoted to ensuring a smooth and compliant process.

For any questions or additional information, our expert team is at your service. Contact us at, (949) 354-2767, or through our live chat for knowledgeable assistance.

Limit 1 per order.

This item is restricted from shipping to the following: California, Colorado, Connecticut, Hawaii, Illinois, Maryland, New Jersey, New York, Oregon, Philadelphia Pennsylvania, Rhode Island, Washington, Washington D.C.