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JMT 308 80% Gen 2 Polymer Lower with Jig - Black

Was: $109.99
Now: $99.99
In Stock! Ships within 1 - 3 Business Days!
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JMT’s beefed up and redesigned Gen 2 Polymer 80% Lower is now available in .308 and 7.62 NATO. Build an AR-10 clone or accurate bench rifle and enjoy critical weight savings without sacrificing reliability.

Upgraded Polymer

This receiver blank was massively reinforced, tested, and re-tested by JMT to guarantee it handles any .30-cal loads you slam through the muzzle. JMT took their existing polymer fiber and upgraded it to be tough, stiffer, and harder, ensuring your receiver is utterly reliable.

LR-308 / Mil-Spec Compatibility

Its 100% mil-spec construction accepts all .308 DPMS components, mil-spec buffer tubes, standard .308 LPKs, and your favorite Magpul magazines. The mag well’s even cut to match! This receiver includes the 80% jig required for drilling the LPK pin holes and trigger cavity, making it a great value for completing your LR-308 or AR-10 clone on a budget. 

Upgraded Features:

  • Extended upper fire control box sections.
  • Upper left magazine well box section.
  • Webbed magazine wells match Magpul mags.
  • Extended bolt release roll pin posts.
  • New JMT Gen2 logo markings.

Manufacturer instructions can be found here.

No FFL is required to purchase this lower receiver. This polymer 80% lower receiver is not considered a firearm and is compliant with ATF receiver blank determinations (Gun Control Act of 1968). Not classified as a firearm as defined in 18 U.S.C. 921(a)(3).

WARNING: Handling firearms parts and accessories can expose you to lead and other petroleum products known to the State of California to cause cancer and reproductive harm. For more information go to:

Shipping Restrictions

Shipping of various parts and/or accessories are prohibited to states and locales (ie New Jersey, California, New York, etc…) with restrictions against certain parts and/or accessories or "assault weapons" (i.e. states with high-capacity magazine restrictions, manufacturing of semi-automatic weapons, etc..). It is your responsibility to be aware of your local firearms laws before purchasing from our website or machining a firearm. We try our best to keep our shipping page current, but laws change daily. only ships within the United States. Federal legislation dictates we cannot ship our products internationally.

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We are a national retailer of individual components and not all products depicted on this website are legal in every state. Shipping of various products found on this website are prohibited to some states (such as California, Connecticut, District of Columbia, Hawaii, New Jersey, New York, Rhode Island, and Washington). The information, pictures, text or products presented on this website are not a representation by us, and should not be understood by you, that any product or completed firearm is legal to assemble or own in your state of residence. We encourage each and every builder to perform their own research about the state and federal laws that apply to them. It is your responsibility to understand the law and we encourage you to consult with an attorney or your local ATF representative.