One Horse Express 22: Factory .22 LR AR With Atrius FRS

One Horse announced the Express 22 Rifle and Express 22 Pistol, two dedicated .22 LR firearms built around Atrius Development Group's three-position Forced Reset Selector, debuting at Booth 3142 during Gun Owners of America's Gun Owners Advocacy and Leadership Summit on August 1 and 2 at the Iowa Events Center in Des Moines. Both models are listed at $1,299.99, reduced from a $1,599.99 MSRP.

This is the second act for the Express line. One Horse launched the 5.56 version in June as the first production AR-15 sold with a forced reset selector fit, timed, and test-fired at the factory, covered in our One Horse Express FRS launch report. The rimfire models carry that same premise into a cartridge that costs a fraction as much to feed.

"Rimfire has always been one of the most practical ways to sharpen fundamentals and put in meaningful range time," said One Horse CEO Jeremy Hammons in the launch announcement. "We wanted to take that experience beyond a basic conversion." One Horse is a family-owned and veteran-owned manufacturer based in Brownstown, Indiana.

The Express 22 uses a .22 LR operating system built specifically around the cartridge, with a rimfire-specific interface that lets the dedicated bolt work with the three-position selector. That distinction is the entire engineering story, and it is why a conversion kit cannot do this.

A forced reset device times itself off the bolt carrier travelling rearward. On a centerfire AR-15 that carrier is heavy, full-profile, and moving on a predictable schedule set by the gas system, which gives the selector cam a consistent window to reset the trigger. A blowback .22 LR has none of that. The bolt is light, there is no gas system, and the carrier bounces. Drop a selector into an ordinary rimfire upper and it short-strokes, doubles, or simply never resets.

Every part of the gun that touches that timing problem is where a factory build earns its money. Anyone who has tried to assemble this combination themselves knows the failure modes, which is the whole subject of our AR22 FRT build guide. One Horse is selling the result instead of the project.

Each Express 22 is a complete serialized firearm on a One Horse lower receiver with One Horse-selected internal lower components, the Atrius FRS being the exception. The controls, ergonomics, and manual of arms are standard AR-pattern, so trigger time on an Express 22 transfers directly to a centerfire carbine.

The two models are mechanically identical apart from barrel length and the stock or brace on the back. Both wear a medium-profile 1:12 twist barrel threaded 1/2x28 under a thread protector, a mil-spec buffer tube, a standard charging handle, and the THRiL RTG grip, which uses a 19.5-degree grip angle and four laser-textured panels.

The rifle uses the THRiL CCS Combat Competition Stock, which adds a flush anti-snag adjustment latch, dual quick-detach sling mounts, and a textured buttpad. The pistol swaps that for a five-position adjustable stabilizing brace in reinforced polymer with an ambidextrous quick-detach sling socket.

A forced reset device turns ammunition cost into the binding constraint on how much you can actually use it. That is the practical case for the Express 22: rimfire runs roughly a quarter the cost of 5.56 per round, so a range session that empties a few hundred cases stops being an expensive decision.

Recoil follows the same logic. The reason to train with a forced reset selector is to learn how to control a fast-cycling gun, and .22 LR lets a new shooter work on grip, trigger discipline, and sight tracking without the muzzle rise of a centerfire carbine masking the errors. The AR-pattern controls mean nothing has to be relearned when they move to 5.56.

The threaded muzzle is the other half of the pitch. Rimfire is the cheapest and quietest suppressor host there is, and a 1/2x28 thread accepts a dedicated .22 can directly. Pair one with subsonic ammunition and every round stays under the sound barrier. Our best .22 LR suppressors guide ranks the current rimfire cans, and the .22 LR ammo guide covers which loads actually cycle a semi-auto reliably, which matters more here than on a bolt gun.

The Express 22 is the second factory rimfire forced reset firearm to market, and it undercuts the first by $278 on the rifle. Tippmann Arms and Rare Breed got there in July with the M4-22 ELITE Rifle FRT at $1,578.00 and the Pistol FRT at $1,608.95, detailed in our Tippmann M4-22 ELITE FRT report.

The mechanisms differ in a way that matters for parts and service. The Tippmann bundles the Rare Breed FRT-15L3, a complete forced reset trigger assembly that replaces the fire control group. The Express 22 uses the Atrius FRS, a safety selector that leaves a conventional trigger in place and does the reset work from the selector itself. A selector-based system puts less stress on the internals and keeps the fire control group standard. Our super safety and forced reset guide breaks down the tradeoffs between the two approaches, and the factory FRT gun roundup tracks every maker now shipping one installed.

If you already own an AR-15 and want the selector on its own, the Atrius Single Side FRS sells standalone at $169.99. That is the centerfire path, and it expects a mil-spec lower with an appropriate buffer. It will not turn a rimfire upper into an Express 22.

Both models list at $1,299.99 against a $1,599.99 MSRP, with One Horse quoting a two-week window from order to shipment. The Atrius Single Side FRS is the included default; the Atrius Ambidextrous FRS is offered as an installed upgrade for $99.99. A spare 25-round Black Dog magazine runs $17.99 at checkout.

One Horse is reserving the initial Express 22 production run for direct consumer orders. Dealer sales open in a second phase once that allocation sells through, which the company frames as a way to build dedicated inventory and sales support for its dealer partners before opening the channel.

As serialized firearms, both models ship to a licensed FFL rather than to your door. If you would rather assemble a centerfire host yourself, our AR-15 builder will check part compatibility as you go.

Forced reset devices covered by the May 2025 Department of Justice settlement are not machine guns under federal law, and the Express 22 is a standard semi-automatic firearm rather than an NFA item. State law is where the restrictions live.

One Horse will not ship the Express 22 to California, Connecticut, Delaware, Florida, Hawaii, Illinois, Maryland, Massachusetts, Minnesota, Nevada, New Jersey, New York, Oregon, Rhode Island, Washington, or the District of Columbia, and does not ship to US territories or internationally. Because the selector ships installed in the firearm, the whole gun inherits those restrictions. Confirm current state and local law before ordering.