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.

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 rifle ships with One Horse's nitride bolt carrier group. Two upgrade BCGs are offered at the cart for $99.99 each: a gold TiN coating and a chameleon PVD finish. Both are cosmetic and optional; the nitride BCG is the functional default. Quantities are limited and One Horse lists the rifle as shipping by July 4th.

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.

Forced reset devices covered by the May 2025 Department of Justice settlement are not classified as machine guns under federal law. The Express is a standard semi-automatic AR-15, not an NFA item. State law is where the restrictions apply.

Because the selector ships in the rifle, the Express can only go to an FFL in a state where the configuration is legal. Confirm your state and local law before ordering.