(3 customer reviews)


Save time & labor with the fully assembled War Lock™ Complete Upper Receiver. This product comes with an enlarged ejection port to accommodate calibers up to and including .50 Beowulf.

NOTE: Does not include Barrel Adapter Assembly, Installation Fixture, Transportation/Storage Cap, Handguard Retainer Assembly, Charging Handle, or BCG.

10 in stock (can be backordered)

SKU: CUR Category: Product ID: 1707


War Lock™ Complete Upper Receiver

The standard AR platform can already fire over 90 calibers, but requires either a dedicated upper receiver for each barrel, or the labor intensive removal and installation of a barrel. The War Lock™ Complete Upper Receiver was created to remove the time and labor required for the customer to install the War Lock Kit on their own AR15 upper receiver.  Our upper receivers come with an enlarged ejection port to accommodate calibers up to, and including .50 Beowulf. Hard-coat anodized aluminum with M4 feed ramps. Made in the U.S.A.

NOTE – The War Lock™ Complete Upper Receiver does not come with a Barrel Adapter Kit, a Charging Handle, or BCG.

The War Lock™ is manufactured from the highest quality materials to provide the longest service life possible. We personally believe that by manufacturing high quality products any need for guarantees or warranties become largely unnecessary. It is our intent to prove that we appreciate your investment in our product. To that end, we diligently strive to provide you with solid value for your trust in us at Frontier Tactical™.

The War Lock™ has been engineered to accept most commonly available barrels, rail systems and hand-guard assemblies. It is possible that the War Lock™ may require special fitting initially, or not be compatible with your components. As there are a multitude of manufacturers and tolerances for different AR builds, we cannot test every one. Please feel free to check our FAQ’s.

AR-15 Complete Upper Receiver - FT

At Frontier Tactical™ we are committed to delivering the highest quality AR and tactical product innovations to you. We pledge to develop and manufacture only technologically superior solutions and promise to pioneer the evolution of firearms for generations to come.

Our mission is to provide our customers with products like no others on the market. Our goal is to forge original solutions to obstacles defined by our customers through the masterful use of technology, innovation and superior skill. We empower our customers, employees, vendors and peers through knowledge, communication and the spirit of ethical cooperation.



Additional information

Weight 2.0 lbs
Dimensions 10.0 × 4.0 × 4.0 in

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Specifications & Notices

Fits – Mil-spec AR-15 lower receivers and barrels. Finish – Hard-coat Anodized Aluminum/Black Oxide.

War Lock™ Complete Upper Receiver includes one enlarged ejection port upper receiver and one Receiver Adapter Assembly.

NOTE – The War Lock™ Complete Upper Receiver does not come with a Barrel Adapter Assembly or Handguard Retainer Assembly.

Additional Barrel Adapter Assemblies are available for separate purchase.

Kit allows for user installation of the War Lock™ Complete Upper Receiver to one AR-15, by simply unpinning takedown/pivot pins. The complete upper receiver system is modularly adapted to other War Lock™-compatible barrel assemblies. Barrel changes are made rapidly; without the need for additional tools. See our line of factory assembled barrel assemblies for “out of the box” and hassle-free modular shooting choices. “Plug and play” simplicity for most calibers.

The War Lock™ is machined from one piece of high quality, billet steel to ensure the longest possible service life. We inspect our components and test them to assure reliability, durability and resistance to corrosion.

The War Lock™ is manufactured in the U.S.A. Frontier Tactical™ is veteran owned and operated in the U.S.A.

Special Notice!

Any changes made to your AR-15 require your knowledge, understanding and compliance with BATFE regulations and local/State/Federal laws. It is the purchaser/owner’s legal responsibility to comply with these laws/regulations.

Specifically, the creation of a Short Barreled Rifle (SBR), Short Barreled Shotguns (SBS), suppressed barrels, or Any Other Weapon (AOW) requires compliance with the National Firearms Act of 1934 (NFA). All NFA rules apply to these modifications. Do not assume anything. Do not break the law.

Frontier Tactical™ LLC and its employees and agents are not liable and will be held harmless from and against all liabilities, legal fees, imprisonment, damages, losses, costs, and other expenses resulting from the illegal use by any purchaser, installer or operator of a firearm with our products.


  1. Ken Hein (verified owner)

    Pure genius, the War Lock Multiple Caliber System is a game changer in the AR world! The folks at Frontier Tactical are incredibly knowledgeable and their customer service is second to none. If you are considering different calibers for your AR the War Lock is the most cost effective way to add 60+ calibers to your arsenal when SHTF!!!

  2. Royce Bartlett (verified owner)

    “Just when you thought the AR-15 had reached it’s apex, the highly innovative multi-caliber War Lock system from Frontier Tactical has produced the next step in its evolution. I’ve never seen, handled or fired such an ingenious and incredibly functional AR platform, and I am as impressed with it today as I was the first day I saw their display at a local gun show. The folks at Frontier Tactical are living proof that America ingenuity is alive and well, and I look forward to seeing what they produce next. ” -Royce Bartlett, host of Shooting Straight Radio Show

  3. Albert Lucas (verified owner)

    “A few months back I walked into a gun show in Pompano Beach with a friend of mine like we do on most weekends. At that show I was instantly struck with a product that I had never seen. It was the War Lock Multi Caliber AR-15 Takedown System by Frontier Tactical. Now, as an Aerospace Tool Room Machinist for a large Jet Engine builder I was instantly impressed by the logical simple design of this product. Another point was the durability of its construction. I instantly struck up a conversation with Scott and Nate and we didn’t leave till all my questions were answered. My buddy walked out with an upper and barrel in 450 Bushmaster which I took home and studied some more. As I said, I was enthralled by the design and you must understand that in my business I see new incredible designs on a daily basis. So much for the design although I must say I made it a point to visit the shop up in Brooksville Florida and after looking at the facility I had Nate break my 300 Blackout and make it a takedown system which took him about 20 minutes.

    Both my buddy and I have shot our War Locks more than a few times with complete reliability. As far as accuracy is concerned you can expect the same ¼ MOA that you have come to expect with any removable and remountable components such as sighting systems etc. If your hobby or for that matter your mission statement requires the dependable option of multi caliber components or concealment. You cannot go wrong with the War Lock System from Frontier Tactical.” -Albert Lucas, West Palm Beach, FL

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