War Lock Upgrade Kit

The War Lock™ transforms your AR platform into the Multiple Caliber System. The AR platform can fire over 90 calibers in its stock configuration. With the War Lock™, the operator can select different calibers without the need for dedicated upper receivers for each barrel assembly.

Installation Videos

SKU: N/A Category: Product ID: 9111


War Lock Upgrade Kit

Frontier Tactical introduces the War Lock Upgrade Kits. Innovation and versatility combine to give your AR-15 rifle new capabilities.  The War Lock™ transforms your AR platform into the Multiple Caliber System.

Unlock your AR.
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™ forges your AR into a Multiple Caliber System.  It replaces the traditional barrel nut and enables the quick installation and removal of War Lock™ equipped barrel assemblies.  By installing the War Lock™ onto your AR, you gain the unmatched capability for caliber modularity. Imagine….one rifle for most calibers.

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 Upgrade Kit includes one Receiver Adapter Assembly; made up of one Lock Collar Assembly, one Lock Ring, one Receiver Adapter, and one Installation Fixture. It also includes one or two Barrel Adapter Assembly Kits; Type 1, 2, or 3 (select Type and quantity). Additional Barrel Adapter Assembly Kits are available for separate purchase.

With the War Lock™, you won’t need to make multiple trips to your vehicle for all the gun cases you take to the range. Simply pack up the rifle, barrel assemblies, bolts, magazines, ammo, and appropriate safety equipment into one case (or one case and additional range bag). Shoot multiple calibers all in one day without the hassle of multiple rifles.

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.

Important Recommendations:
As with most AR accessory installations, Frontier Tactical recommends that the initial assembly of our kit be installed by a competent gunsmith or armorer. We recommend that headspace checks be done prior to firing for the first time.  It is the responsibility of the user to ensure that appropriate safety checks have been done to their weapon PRIOR to firing with our kit.  The user is responsible for compliance with all legal requirements for their area.  Installation of our kit may void any manufacturer warranties. User assumes all risks and liability where applicable by law.

War Lock™ Highlights:

  • Fast caliber changes
  • New storage capabilities
  • Easier to transport
  • More effective access for cleaning
  • Intuitive accessory combinations
  • Quick assembly and disassembly
  • Durable materials for lifetime use
  • Ergonomic design
  • Modular system


NOTE: Our products are made to order! Due to the newness and popularity of our flagship product, please allow up to 30 days for your order to be delivered.Made-in-USA

Additional information

Weight N/A
Dimensions N/A
Type of Kit

Type 1 Kit, Type 2 Kit, Type 3 Kit

Number of Barrel Adapter Kits

One Barrel Kit, Two Barrel Kit

Specifications & Notices

Fits – Mil-spec AR-15 upper receiver and barrels. Finish – Black Nitride.

Kit allows for user or gunsmith installation of the War Lock™ system to one AR-15. Once installed to the upper receiver, the 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 and receivers for “out of the box” and hassle-free modular shooting choices.

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.

It is engineered and designed to occupy the same “footprint” of the standard AR-15 barrel nut. This allows for the compatibility of most “off the shelf” AR-15 parts and accessories.

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.