The One Horse Express 16-Inch FRS Rifle: Factory Built and Ready to Ride

Some rifles are assembled from a list of parts. Others are built as a complete system. The One Horse Express 16-inch 5.56 NATO/.223 rifle belongs in the second category.

Made in the USA and factory-equipped with the Atrius Single Side FRS, the One Horse Express brings together a practical 16-inch configuration, a mid-length gas system, modern controls, and full-length M-LOK capability. The result is a clean, purpose-driven AR-platform rifle built for shooters who want something more distinctive than a basic off-the-rack setup.

What Makes the One Horse Express Different?

The defining feature of this rifle is the factory-installed Atrius FRS selector system. Instead of treating the FRS as an aftermarket add-on, One Horse builds the rifle around it. The selector system is fitted, timed, and tested at the factory as part of the complete firearm.

That matters because proper component fit and system balance are important in any specialized AR configuration. With the One Horse Express, the rifle arrives as a matched factory package rather than a collection of parts that still needs to be sorted out after purchase.

WHO MAKES IT?

The people behind one horse are humble, driven, and passionate. Their passion is translated clearly into their product!

A Practical 16-Inch 5.56 Platform

At the center of the rifle is a 16-inch SOCOM-profile barrel chambered in 5.56 NATO/.223 Remington. The barrel uses a 1:8 twist rate, a versatile choice for many commonly available 5.56 and .223 projectile weights.

The mid-length gas system gives the Express a well-rounded operating setup, while the 1/2x28 muzzle threading and included A2 muzzle device keep the front end familiar and compatible with widely used AR-pattern components where lawful.

Surrounding the barrel is a 15-inch Express M-LOK handguard. Its slim, full-length design gives the shooter ample room for support-hand placement and the addition of compatible lights, sling hardware, hand stops, or other mission-appropriate accessories.

Built with Thoughtful Controls and Furniture

The One Horse Express is fitted with a Breek Warhammer Mod2 ambidextrous charging handle, giving both right- and left-handed shooters convenient access to the action. At the rear, a mil-spec buffer tube supports a THRiL CCS stock, while the THRiL RTG Rugged Tactical Grip provides a modern, functional interface.

Together, these components give the rifle a clean factory appearance without sacrificing the modularity that makes the AR platform so useful.

One Horse Express 16-Inch Specifications

Feature	Specification
Manufacturer	One Horse
Model/SKU	One Horse Express OHX-AI01
Caliber	5.56 NATO / .223 Remington
Barrel	16-inch SOCOM profile
Twist Rate	1:8
Gas System	Mid-length
Muzzle Thread	1/2x28
Muzzle Device	A2
Handguard	15-inch Express M-LOK
Selector	Atrius Single Side FRS
Charging Handle	Breek Warhammer Mod2, ambidextrous
Grip	THRiL RTG Rugged Tactical Grip
Stock	THRiL CCS
Buffer Tube	Mil-spec
Magazine	30-round magazine where lawful
Country of Origin	USA

Who Is This Rifle For?

The One Horse Express is aimed at the shooter who wants a complete factory-built FRS rifle without having to source, fit, and troubleshoot a specialized parts combination independently. It also makes sense for AR enthusiasts looking for a full-size 5.56 rifle with practical furniture, ambidextrous charging controls, and room to configure the handguard around their preferred setup.

Its standard 16-inch barrel and adjustable stock create a familiar rifle format, while the Atrius FRS and One Horse factory treatment give it an identity all its own.

Available Through Eleanor Armory

The One Horse Express 16-inch rifle is built to order and available through Eleanor Armory. The firearm ships free from Eleanor Armory to an eligible licensed FFL dealer.

View the One Horse Express 16-inch 5.56 NATO/.223 rifle with Atrius FRS

Have questions about the rifle, the transfer process, or whether this configuration is available in your area? Contact Eleanor Armory before ordering. We are happy to help you understand the process and choose the right setup for your needs.

Factory built. Factory fit. Ready to ride.

This is a serialized firearm and must be transferred through a licensed FFL dealer. The purchaser is responsible for confirming eligibility and compliance with all federal, state, and local laws. Magazine, selector, feature, and firearm-configuration restrictions may apply. Product components and availability are subject to manufacturer changes.