Radical Firearms 16″ 6.5 Grendel AR 15 Complete Upper Receiver with M-LOK Handguard

SKU: RF00421

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AT3™ Red Tail™ Rifle Scope with Mount – 1-6x Magnification


Complete Budget-Friendly Upper Receiver for 6.5 Grendel AR Builds

The Radical Firearms 16″ 6.5 Grendel Complete Upper Receiver is a great way to start your 6.5 Grendel AR build. It is an outstanding choice for long-range, high-value builds ready to be mounted to any Mil-Spec AR-15 lower receiver. The upper comes complete and assembled with a “Pepper Pot” muzzle brake, Charging Handle, Nitride Bolt Carrier Group, and a Radical Firearms 15″ RPR M-LOK Free Float handguard.

It is the perfect choice for the novice or advanced shooter wanting to finish out that build and hit the range.

Forged From 7075 T6 Aerospace-Grade Aluminum

The upper receiver is forged from 7075 T6 aerospace-grade aluminum and features a hardened Type III Anodized finish for dependable, quality shooting. The barrel features a Medium Contour Profile barrel made for prolonged periods of fire and machined from 416R Stainless Steel.

The low profile medium length gas system is fine-tuned for proper cycling and the free float rail system will keep your hands cool while increasing accuracy.

Radical Firearms offers a Lifetime Warranty on all their products for as long as you own the product.


  • Barrel Length: 16″
  • Gas System: Medium Length
  • Barrel Profile: Medium Contour Profile
  • Barrel Material: 416R
  • Barrel Finish: Stainless Steel
  • Muzzle Thread: 5/8×24
  • Chamber: 6.5 Grendel
  • Twist Rate: 1:8
  • Barrel Extension: M4 Feed Ramp
  • Gas Block Type: .750 Low-profile Gas Block
  • Muzzle Device: “Pepper Pot” Brake
  • Upper Receiver Material: Forged 7075 T6
  • Upper Receiver Style: M4 MIL-STD
  • Upper Receiver Finish: Type III Anodizing
  • Forward Assist: Yes
  • Dust Cover: Yes
  • Handguard Type: Free Float
  • Handguard Style: M-Lok Thin Rail
  • Handguard Length: 15″
  • Charging Handle: MIL-STD
  • Bolt Carrier Group Included: Yes
  • BCG Finish: Nitride

Have Questions About this Product?

The AT3 Tactical store has a 90 day no-hassle return policy for products in good condition. You can view the full details of our return policy here.

If you encounter an issue or defect with a product after 90 days of your purchase, you can refer to the manufacturer for a warranty claim. Their policies are below.

Radical Firearms Warranty

How do I return an item?

With the exception of the following listed items, all purchases made from Radical Firearms carry a five (5) calendar day return period that starts the day of receipt of the order as reported by the delivery service. Within that time, a customer may return items ordered for a full refund (less shipping costs if the entire order is returned) as long as they are unopened and unused. If the packaging has been opened, the items may still be returned however will be subject to a 20% re-stocking fee.

Order(s) cancellations for all items prior to shipment will be assessed a 10% cancellation/restocking fee.

The following items may not be returned and all sales are considered final.

  • Firearms (which include lower receivers)
  • Upper Receivers
  • Special Orders

Prior to returning an item, please send an email to info@radicalfirearms.com referencing the order number and item(s) being returned. Any shipment that arrives without prior notification will be marked “Return to Sender” and returned at the sender’s expense.

The customer is responsible for arranging shipping of any returned items. Radical Firearms highly recommends the use of an insured, trackable method of returning products such as UPS or FedEx. Responsibility for products damaged in transit while returning items is the responsibility of the customer, not Radical Firearms . Once the returned item is received, the customer will be notified of the progress of the return.

Returned orders that qualified for free shipping will have the actual cost of shipping deducted from the returned amount.

Contact Details:

  • Email: info@radicalfirearms.com

Disclaimer: Manufacturer’s warranty is subject to change without prior notice.