JR-15 Mk 5 Mod 4 80% Lower Receiver


Out of stock
Out of stock
Out of stock
Out of stock

JR-15 Mk 5 Mod 4 80% Lower Receiver


$85.00 
  • SKU: 80SLMK5M4
  • Shipping:  
  • Return Policy: We want you to be satisfied with your purchase. If you need to return merchandise within the first 14 days of delivery please follow the steps outlined below. Returns after 14 days will not be accepted. **Please note that firearm purchases that are accepted from the transferring FFL are considered used firearms and returns will NOT be guaranteed. Inspect it BEFORE accepting the transfer. All sales are final on special orders, products sold "as is" or "used" or that have been installed or used after receipt. **NFA items, custom firearms, electronic sights and optics, ammunition. Unless received defective, these items are not returnable or refundable. Call us at 804-869-8960 or send your request for a return to freedomforgearmory@comcast.net to obtain authorization. No returns of merchandise will be accepted without prior authorization. All returns on orders paid by a credit card will receive a credit to the card used on the purchase (or store credit at our discretion) once confirmation of receipt of merchandise has been made and inspection has been completed. Depending on your financial institution, refunds are credited between 3 to 5 business days after issuance. All cancelled orders that paid with a money order or cashier's check will have the refund issued as store credit. To qualify for a refund on an item that is not defective, all returned merchandise must include the following: The merchandise must be in the original packaging. The merchandise must be unused. Products showing use will not be refunded or exchanged. Include the following in package: A copy of your original invoice and packing slip The reason for your returned merchandise. All return merchandise shipments must be pre-paid, no COD. You must send your returned merchandise using either UPS, FedEx, or USPS according to their restrictions and provide us with tracking information. You must obtain a Return Authorization PRIOR to returning the item by contacting Freedom Forge Armory LLC at 804-869-8960 or freedomforgearmory@comcast.net. Please ship your returned item to: Freedom Forge Armory LLC Attn: Returns. 7400 Brandy Creek Dr. Mechanicsville, VA 23111 Upon receiving your package, and verification of the item is made, you will receive an e-mail with the status. This process can take up to a few weeks from start to finish. Please Note: You will be responsible for covering the Shipping Fee on returned merchandise that is not-defective. A 20% Restocking Fee will apply to any returned merchandise. Firearms that are not defective and in the possession of your FFL will have a 20% Restocking Fee AND a shipping charge deducted from your refund. Any variance to this policy may result in no refund or a partial refund.

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This Freedom Forge Armory 80 percent lower is not an FFL item and is classified by the ATF as a non-firearm. Made from 7075 T6 heat-treated aluminum, this lower features flared and broached magwells and is "finished in white", tumbled and ready to be bead blasted before anodizing or KG Gunkote. All that's required is machining of the trigger and the safety well before it's a fully functional, mil-spec lower receiver. These are the same raw billets that all of our 5.56mm Joint Rifles receivers are machined from.

The Mk5 Mod 4, 80% Lowers comes with a tension screw hole drilled and threaded for a 1/4"x28 set screw.



  • 80% machined (just needs trigger and safety well machined)      
  • 7075 aluminum        
  • T6 heat treated        
  • Magwells are flared and broached