In 2024, TandemKross (TK), best known for its high-quality competition upgrades for rimfire platforms, launched the first ever lower-receiver assembly designed for the rimfire Ruger 10/22 platform. Dubbed the Manticore X, it provides a set of features and configuration options unavailable with the typical trigger groups and stocks made for this popular semi-automatic platform. In most cases, a 10/22 trigger group’s polymer or aluminum housing supports the carbine’s trigger guard, trigger, fire-control group, external safety button and magazine-release mechanism. The trigger group is secured to the serial-numbered receiver using two cross pins that are held in place by setting the action into either a shoulder stock or chassis system. Once the action is secured to the stock using the takedown screw, the carbine is ready to fire.
The CNC-machined aluminum housing of the Manticore X fills the same mechanical roles as the usual 10/22 trigger housing, however, it has been extended and modified to take the place of a stock, much like the lower receiver of an AR-15 rifle. In addition to its fire-control group and external controls, the Manticore X supports the magazine and provides a mounting position for removable and interchangeable AR-15 pistol grips. At the rear is an extension that supports a short Picatinny rail section for attaching either fixed or folding shoulder stocks. The hardware supplied with the Manticore X includes a set of cross pins with ball detents that secure them into the receiver.
This assembly is designed to be used as a drop-in component with a variety of Ruger-brand and aftermarket 10/22-pattern fixed-barrel receivers. Simply remove the action from the stock and the trigger group from the receiver as you would for routine cleaning. Then install the Manticore X into the receiver in place of the trigger group. Lastly, attach an AR pistol grip and a rail-mounted buttstock of your choice. TandemKross offers the latter, which, along with the company’s fore-end, is shown in the photo above.
The Manticore X ships ready to use and is loaded with competition upgrades, including TK’s Ultimate Trigger Kit sporting the flat-faced Victory trigger shoe. This single-stage trigger is adjustable for a pull weight from between 2 lbs., 8 ozs., to 5 lbs. and for overtravel. The extended, textured, aluminum Fireswitch magazine-release lever is bi-directional, meaning it can be either pressed forward or pulled back to eject the magazine. Other upgrades include the oversized integral trigger guard, a Bolt Keeper bolt-hold-open lever with an extended knob, bilateral Cornerstone Rotary safety selector levers set into the front of the trigger guard and the company’s rubber Shock Block Bolt Buffer.
The base of the two-slot stock-mounting rail is cut at an angle and secured with a round connector that also serves as a QD sling port. The connector can be removed to allow the rotation of the aluminum rail in order to provide either a straight-stock configuration or to give the stock a 12-degree downward cant to better fit the height of the optic being used.
To evaluate this lower’s features, it was incorporated into a complete 10/22-pattern carbine build and test fired at the shooting range. The trigger was set to 3 lbs., 8 ozs., for our range evaluation, during which it exhibited a crisp break, a short arc of travel and cycled smoothly. The other competition-grade controls were just as smooth and reliable in their operations, providing for a positive and enjoyable shooting experience.
By offering a complete set of control upgrades, an enhanced trigger and the means to install your choice of AR pistol grip and rail-mounted stocks in a convenient drop-in assembly, the Manticore X from TandemKross allows shooters to add new modularity and functionality to Ruger’s beloved 10/22 platform. The Manticore X is available in either an all-black finish or black with red appointments for a suggested retail price of $500.
For more information, visit tandemkross.com.
