One Horse Express FRS: First Factory Forced-Reset AR-15, $999

Every forced reset build until now started with the buyer doing the work: source a selector or trigger, swap a buffer, find a low-shelf lower, time it, and hope it runs. The One Horse Express ends that. It is the first production AR-15 sold with a forced reset selector installed, fit, timed, and test-fired at the factory. You buy a complete rifle, not a project.

It is a collaboration, not a parts-bin assembly. One Horse, a family-owned manufacturer in Brownstown, Indiana, developed the rifle with Atrius Development Group, the company behind the selector. "This rifle was built to run," said One Horse CEO Jeremy Hammons in the June 19 launch announcement, with Atrius founder Ryan Spadafore framing it as the FRS reaching the production line after years of setting the aftermarket standard.

That matters because the failure mode for forced reset devices is almost always integration, not the device itself. An FRS dropped into a rifle with the wrong buffer weight or a high-shelf lower short-strokes and stops resetting. One Horse engineered the Express from the ground up around the selector, so the buffer, shelf, and gas system are matched to it rather than worked around it.

The selector itself is the Atrius Single Side FRS, a part we reviewed on its own and a known quantity in the forced reset space. One Horse labels its three positions Safe, Semi, and Super Semi, with Super Semi being the forced reset mode that resets the trigger against your finger as the carrier cycles. For a full breakdown of how the selector works versus a trigger-based FRT, see our Atrius FRS review and the Super Safety and forced reset guide.

Under the forced reset headline, the Express is a conventional, well-specified 16-inch carbine. Nothing here is exotic, which is the point: a nitride-finished CrMoV SOCOM-profile barrel, a low-profile staked steel gas block, and a mid-length gas system are the right host for a reliable FRS.

The Atrius Single Side FRS is a drop-in safety selector machined from heat-treated 4140 steel. In its third position it mechanically leverages the carrier to reset the trigger as the rifle cycles, delivering rapid semi-automatic fire without replacing the trigger group. Because it keeps your mil-spec fire control group, it puts less stress on internals than a trigger-based forced reset trigger.

If you already own an AR-15 and want the same capability, the selector is sold on its own. The single-side version is $199 and the ambidextrous version is $249. Plan on an H2 or H3 buffer and a low-shelf lower, the exact setup One Horse builds into the Express, or you will fight short-stroking in the third position.

The single most common forced reset complaint is a rifle that runs fine in semi but stutters or fails to reset in the third position. The cause is almost always carrier velocity and timing. Too light a buffer and the carrier moves too fast and unlocks the reset; the wrong shelf height and the selector cam cannot fully engage.

One Horse addresses both by building the Express with an H2 buffer and a low-cut fire control shelf from the start. The heavier buffer slows the carrier into the timing window the FRS needs, and the low shelf gives the selector cam full travel. This is the same integration work an experienced builder does by hand, done at the factory and validated before the rifle ships.

If you are tuning a forced reset build of your own, buffer weight is the first lever to pull. Our AR-15 buffer systems guide covers H1, H2, and H3 weights and when to step up, and the forced reset buyer's guide compares every current FRS and FRT option side by side. Our FRT compatible guns guide maps which platforms have a forced reset path at all.

One Horse cut the same factory-timed Atrius package to 10.5 inches on July 30, 2026 with two brace pistols (covered below). The line also extended into rimfire in August 2026 with the Express 22 Rifle and Express 22 Pistol, dedicated .22 LR firearms running the same Atrius selector at $1,299.99 each. See our One Horse Express 22 coverage for the rimfire spec split and how it prices against the Tippmann.

One Horse cut the same factory-timed Atrius FRS package down to two 10.5-inch 5.56 pistols. They were still in stock, three-day ship, direct from theonehorse.com as of August 20, 2026. The pistols are the short Express, not a new platform.

Buy the 16-inch unless you specifically need a brace gun. Quad is a rail/brace preference tax, not a better FRS. Shooting News Weekly rounded the pistols to $1,099 / $1,199; the live One Horse cart as of August 20 shows $1,099.99 / $1,199.99.

Cart extras on all three SKUs: ambidextrous Atrius for +$99.99; TiN, chameleon PVD, or NiB BCG for +$99.99 each. Skip every complete Express if you already have a mil-spec AR with H2/H3 and a low-cut shelf; the roughly $199 Atrius standalone is the same selector. Shop the Atrius FRS.

The Express launches at $999.99, down from a $1,199.99 MSRP. For a complete, factory-tuned forced reset rifle that price is aggressive: a comparable do-it-yourself build runs a $700 to $900 rifle plus a $199 to $249 selector plus buffer and lower-shelf work, before you account for the time and the risk of getting the timing wrong.

The standard Express ships with One Horse's nitride bolt carrier group. Cart extras shared across the rifle and both 10.5 pistols: ambidextrous Atrius for +$99.99, and TiN, chameleon PVD, or NiB BCG upgrades for +$99.99 each. The nitride BCG is the functional default. Quantities are limited.

As a serialized firearm, the Express ships to a licensed FFL, not to your door. Want to spec your own forced reset carbine instead? Start in our AR-15 builder or browse the full parts catalog at /catalog.

One Horse added two limited-time Cerakote finishes to the Express lineup on July 3, 2026: American Camo, a red, white, and blue pattern, and Woodland Camo, an M81-style green and brown finish. Both are the exact same Express rifle covered above, the Atrius FRS, the 16-inch SOCOM-profile barrel, the H2 buffer and low-cut shelf, just wearing a different finish. MSRP on the Cerakote editions is $1,299.99, a $100 premium over the standard nitride-finished Express, and they ship only through One Horse at theonehorse.com/express.

"This limited release is about giving customers a way to express who they are without giving up the foundation the Express was built on," said Jeremy Hammons, CEO of One Horse, in the July 3 launch announcement. "Some folks want American Camo because it speaks to pride in this country. Some want Woodland Camo because it feels familiar, practical and field-ready. Either way, they're getting the same rifle underneath, built right, tuned as a system and ready to run."

Everything that made the base Express notable still applies: the Atrius FRS is fit, timed, and test-fired at the factory, and the buffer and shelf are matched to the selector rather than left for the owner to sort out. The Cerakote editions are a finish option layered on top of that same build, not a separate SKU with different internals. As with the standard Express, quantities are limited and the rifle ships to a licensed FFL in states where forced reset devices are legal.

Forced reset devices covered by the May 2025 Department of Justice settlement are not classified as machine guns under federal law. The 16-inch Express with a stock is a standard semi-automatic AR-15, not an NFA item. The 10.5s ship as brace pistols, which are also a non-NFA configuration. A stock on a 10.5 without NFA paperwork is an SBR. State law is where the forced-reset bans live.

Because the selector ships in the firearm, Express SKUs only go to an FFL in a destination One Horse will serve. Confirm your state and local law before ordering.