The .22 LR has introduced generations of Americans to shooting. It is affordable, widely available, easy to handle and one of the best cartridges for building real confidence behind a firearm.
But not every 22 caliber AR platform is built the same.
Some shooters use a .22 LR conversion kit inside an existing 5.56 or .223 rifle. That can be a convenient way to send rimfire ammunition through a centerfire platform, but it remains exactly what the name suggests—a conversion.
The One Horse Express 22 takes a different approach.
Available as the 16.1-inch Express 22 Rifle and the 12.1-inch Express 22 Pistol, the Express 22 is a complete, dedicated .22 LR firearm. Its barrel, chamber, bolt system and operating components are built specifically around the 22 Long Rifle cartridge. That dedicated upper is paired with a One Horse lower receiver, One Horse-tuned components and the Atrius Development Group Ambidextrous Forced Reset Selector.
It is not a collection of parts that the customer has to diagnose, balance or tune.
It is an entire system that comes out of the box tuned and ready to run.
The terms .22 LR, 22 LR and 22 Long Rifle all refer to the same rimfire cartridge. It is commonly used for firearms training, recreational shooting, competition and high-volume range days.
People also frequently search for “22 caliber,” although that term describes a broader family of cartridges. The Express 22 is chambered specifically for .22 Long Rifle.
For new shooters, .22 LR offers manageable recoil and less noise than most centerfire rifle cartridges. For experienced shooters, it creates an affordable way to work on fundamentals, movement, transitions and weapon handling without burning through a full loadout of centerfire ammunition.
That combination has made .22 LR one of the most useful cartridges in America.
The Express 22 was built to get everything possible out of it.
A typical .22 LR conversion kit replaces the centerfire bolt carrier group and allows 22 Long Rifle ammunition to be fired through an existing 5.56 or .223 barrel.
It is a practical concept, but the firearm is still built around a different cartridge. The .22 LR ammunition is operating through a chamber and barrel originally designed for centerfire ammunition. The shooter may also have to swap components, confirm compatibility and find the ammunition that works best with that particular combination.
The Express 22 eliminates that compromise.
Its dedicated chamber, barrel and bolt system are designed specifically for .22 LR. There is no centerfire chamber adapter bridging two different systems. There is no need to continually convert a primary rifle between calibers. There is no need to disturb an existing optic, zero or centerfire configuration every time you want an affordable range session.
You grab the Express 22, load it and run it.
The Express 22 is not simply a complete .22 LR upper receiver.
It is a complete firearm.
One Horse does the work here. We pair the dedicated .22 LR upper with a complete One Horse lower receiver, the Atrius Development Group Ambidextrous Forced Reset Selector and the supporting components required to make the platform function as one complete system.
That removes the guesswork that often comes with building a rimfire platform yourself. Customers do not have to source a lower, determine selector compatibility, experiment with component combinations or spend their first range session chasing adjustments.
We configure it. We test it. We send it out ready to run.
The Express 22 lower also gives the owner more than a dedicated rimfire platform. It is compatible with One Horse Express uppers, allowing customers to use the same complete lower across compatible Express configurations.
That means the customer is not buying a one-purpose upper receiver. They are getting a complete firearm and a foundation for the broader Express Series.
Any alternate configuration must comply with all applicable federal, state and local laws.
The Express 22 does not send a .22 LR projectile through a barrel originally designed around .223 Remington or 5.56 NATO. Its chamber, bore and operating system are purpose-built for 22 Long Rifle ammunition.
That dedicated configuration supports more consistent alignment and repeatable performance while removing the compromises that come with operating rimfire ammunition through a centerfire barrel.
A conversion kit requires the shooter to open an existing rifle, remove components and install the conversion system. Returning to the original caliber means reversing that process.
With the Express 22, your rimfire platform stays a rimfire platform. Your centerfire rifle remains configured exactly the way you left it.
That matters when your optic is zeroed, your accessories are placed where you want them and your primary rifle is already set up for a specific purpose.
The Express 22 combines a dedicated rimfire upper, stainless-steel bolt system, rimfire-specific operating components, a serialized One Horse lower and the Atrius FRS.
The trip system and anti-bounce weight are installed as part of the factory configuration. The upper and lower are paired, configured and tested together instead of asking the owner to build a reliable operating system one component at a time.
This is where the Express 22 separates itself from a standalone upper or conversion kit.
The work has already been done.
No sourcing parts. No guessing at compatibility. No chasing adjustments at the range.
The result is simple: a complete firearm with no owner tuning required before the first range session.
The Express 22 maintains the familiar handling characteristics and controls of an AR-pattern firearm. That makes it valuable for practicing weapon manipulation, loading, positional shooting, target transitions and other fundamentals that transfer directly to a centerfire AR.
The Express 22 Rifle includes a THRiL CCS Combat Competition Stock, while the Express 22 Pistol is equipped with an SBA-6 Stabilizing Brace. Both models include the THRiL RTG Grip with its 19.5-degree grip angle and laser-textured panels.
It feels familiar because it is a complete AR-pattern firearm—not a temporary conversion.
The greatest advantage of .22 LR may be simple economics.
Lower ammunition costs make it easier to train longer, bring new shooters to the range and work through drills without watching every pull of the trigger turn into a major expense.
The Express 22 is built for training, recreational shooting and high-volume range use. It gives experienced shooters a practical training platform while creating an approachable starting point for the next generation.
More ammunition. More repetitions. More meaningful range time.
The Express 22 is built on the same complete-system philosophy that defines the One Horse Express Series.
At the center of the lower receiver is the Atrius Development Group Ambidextrous Forced Reset Selector, or FRS. It provides three selector positions:
A rimfire-specific interface allows the dedicated bolt system to operate with the Atrius FRS. The lower, upper and operating components are configured together before the firearm reaches the customer.
That is an important difference.
Building a dependable .22 LR platform around forced reset technology can require careful attention to bolt velocity, ammunition, component weight and selector compatibility. The Express 22 removes that burden from the customer.
The work has already been done.
No collection of aftermarket parts. No guessing at combinations. No chasing adjustments at the range.
One complete platform. Tuned and ready to rip.
The One Horse Express 22 is offered in two configurations.
The Express 22 Rifle features a 16.1-inch dedicated .22 LR barrel and the THRiL CCS Combat Competition Stock. It provides the traditional handling and balance of a full-size AR-pattern rifle.
It is an excellent option for fundamentals training, recreational shooting and shooters who want a dedicated 22 caliber rifle with familiar controls.
The Express 22 Pistol features a 12.1-inch dedicated .22 LR barrel and an SBA-6 Stabilizing Brace. Its shorter configuration provides a compact and highly maneuverable rimfire platform.
Both models share the same core purpose: deliver a complete .22 LR system built around repeatable performance and dependable operation.
The choice comes down to which configuration fits the shooter.
Rimfire ammunition can vary considerably between manufacturers, product lines and individual lots. Differences in velocity, bullet weight and consistency can affect the operation of any semi-automatic .22 LR firearm.
Throughout One Horse testing, CCI 40-grain Mini-Mag ammunition delivered the best overall performance in the Express 22. It is our recommended starting point for dependable operation right out of the box.
The Express 22 arrives factory-configured with no owner tuning required. That does not mean every type of bulk, standard-velocity or subsonic ammunition will perform exactly the same. If you are testing a new load, begin in Semi and confirm dependable operation before increasing your shooting pace.
Reliable ammunition gives a reliable platform the opportunity to do what it was built to do.
Run.
The .22 LR cartridge naturally leaves more residue inside a firearm than many centerfire cartridges. Powder residue, bullet lubricant and rimfire debris can accumulate around the chamber, bolt face, extractor and operating surfaces.
Regular cleaning helps maintain dependable operation, especially after high-volume range sessions.
Before performing any maintenance:
After verifying that the Express 22 is completely unloaded, separate the upper and lower receivers using the takedown pins. Remove the charging handle and dedicated bolt assembly from the upper in accordance with the current One Horse owner instructions.
The factory-installed trip and anti-bounce components are part of the tuned operating system. Keep those components together and do not change their configuration during routine cleaning.
For normal maintenance:
Reinstall the charging handle and bolt assembly in the reverse order of removal. Confirm that the assembly is fully seated and moves freely before reconnecting the upper and lower receivers.
Complete the manufacturer-recommended function check before returning the firearm to service. Do not disassemble the bolt internals or alter the factory-tuned components unless you are following current One Horse service instructions.
If anything appears damaged, excessively worn or incorrectly positioned, stop and contact One Horse before firing.
Yes. The names .22 LR, 22 LR and 22 Long Rifle refer to the same rimfire cartridge. “22 caliber” is a broader description that may refer to several different cartridges.
No. The Express 22 is a complete, dedicated .22 LR firearm. It uses a rimfire-specific barrel, chamber, bolt system and operating interface rather than firing through a converted 5.56 or .223 barrel.
No. The Express 22 is sold as a complete firearm. One Horse pairs the dedicated .22 LR upper with a complete One Horse lower receiver, the Atrius Ambidextrous FRS and the supporting components needed to create a factory-configured system.
No owner tuning is required. The upper and lower are configured and tested together as a complete firearm before leaving One Horse. Quality high-velocity ammunition is recommended for the most consistent performance.
CCI 40-grain Mini-Mag delivered the best overall performance throughout One Horse testing and is our recommended ammunition for the Express 22. As with any semi-automatic rimfire firearm, performance may vary between ammunition types and production lots.
The Express 22 Rifle uses a 16.1-inch barrel and THRiL CCS stock. The Express 22 Pistol uses a 12.1-inch barrel and an SBA-6 Stabilizing Brace.
A dedicated .22 LR platform provides a barrel, chamber and operating system designed specifically for the cartridge. It also eliminates repeated component swaps and allows the shooter to leave a centerfire rifle configured and zeroed.
Yes. The Express 22 lower is compatible with One Horse Express uppers, giving owners a complete lower that can serve as the foundation for other compatible Express configurations. All configurations must comply with applicable federal, state and local laws.
Yes. The Express 22 is a complete AR-pattern rimfire platform designed to provide familiar handling, controls and ergonomics.
There will always be a place for conversion kits. They provide a convenient way to fire .22 LR through an existing centerfire rifle.
The Express 22 was built for the shooter who wants more.
A dedicated barrel. A dedicated chamber. A dedicated bolt system. A complete One Horse lower. An Atrius Ambidextrous Forced Reset Selector. Every major component configured to work together before the firearm reaches the customer.
This is not just a complete upper.
It is a complete firearm.
One Horse does the work. The customer gets a platform that is tuned, tested and ready to run, plus a complete Express lower that is compatible with One Horse Express uppers.
No conversions. No collection of mismatched parts. No owner tuning required.
Just a dedicated .22 LR platform built for affordable training, serious range time and pure rimfire fun.
The One Horse Express 22.
Built to Run.™
