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One Horse Express

10.5" Express QUAD 5.56/.223 Atrius FRS Pistol

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SKU OHX-APQ01UPC 850088856040

A black American-made AR-style pistol featuring a modular handguard, ergonomic pistol grip and polymer magazine on a white background.

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  • Limited Lifetime warranty
  • Ships to your dealer
  • Free shipping

How buying a pistol works

  1. Order online.Pick any options above, then check out.
  2. Choose your dealer.At checkout choose a dealer that is close to you for transfer.
  3. Pick it up.Your dealer checks your ID, runs the required background check and hands it over. You must be at least 21 to buy this pistol.

Questions before you buy? Call 812-200-0305 or email customerservice@theonehorse.com.

What’s in the build

One Horse Express Specifications

  • Single Side Atrius SelectorTested, Tuned and Ready for the Range!
  • Breek Warhammer Mod2Ambi Charge Handle
Barrel
Caliber5.56mm NATO
Barrel Length10.5 in.
Barrel ProfileMedium
Muzzle Thread1/2×28
Twist Rate1:7
Gas SystemCarbine
Muzzle DeviceA2
Upper
Handguard Length9.25 in.
Charging HandleBreek Warhammer mod2
Lower
SelectorAtrius Single Side FRS
Buffer TubeMil-Spec
Furniture
GripTHRiL RTG - Rugged Tactical Grip
In the box
Magazine30 Round Magazine
Origin
ManufacturerOne Horse
Country of OriginU.S.A.
Test FiredEvery firearm is test fired before it ships
Videos

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Customer Reviews

Reviews

Real feedback from customers who have experience with this product.

5.0
★★★★★
6 reviews
Night H. Sep 19, 2026
★★★★★

I got the chance to shoot the 10.5 Express Quad Rail at a pistol/rifle performance class. As a fan of GWOT era rifles, I immediately noticed the quality and aesthetic of this rifle the moment my hand C clamped the Quad rail. It just felt right. With a quick smooth transition to the third position of the selector, I pulled the trigger and was surprised. There was no “sweet spot” like some of the other forced resets out there. My own rifle included. The entire magazine emptied without interruption. The rifle remained completely flat and controllable throughout the string of fire. Pairing this rifle with the Atrius forced reset selector, resulted in the perfect match. A quality American Made Rifle, tuned to run from the factory. One Horse stands above the rest.

Khalid Y. Sep 15, 2026
★★★★★

I love it. I love the customer service every time you call professional answer, professional response. You don’t have to be on hold for And I love the one horse express. I love it. I think every true American need to have one thank you for such a beautiful rifle and a pistol

Patrick H. Aug 19, 2026
★★★★★

Always been a quad rail guy so this one was a easy choice. Feels tough, balances better than I expected and the 10.5 barrel makes it super handy. The Atrius setup makes it even more fun.

Preston H. Aug 08, 2026
★★★★★

Wanted something short with a quad rail and this checked all the boxes. Its built solid and feels like it can take some abuse. Havent had any issues and its quickly become one of my favorites.

Richard P. Jul 25, 2026
★★★★★

Ive had a few different AR pistols over the years but this 10.5 QUAD Express is probably one of the better put together ones Ive owned. First thing I noticed was how solid the whole thing feels. Nothing loose or rattling around and the fit between the upper and lower is nice and tight. Im a sucker for the old school quad rail look and this one gives you plenty of room for whatever accessories you wanna run without making the gun feel ridiculously bulky. The 10.5 barrel keeps it short and easy to handle, but it still balances pretty good in the hands. The grip and brace are comfortable and the Warhammer charging handle is easy to grab from either side. I also like that the Atrius FRS was already installed, timed and tested at the factory instead of having to mess with getting everything setup myself. Finally got it out to the range and it ran great. The FRS takes a little getting used to if youve never used one before, but once you figure it out this thing is seriously fun. Everything felt smooth and I didnt notice any weird issues or parts coming loose. Overall its a tough little setup with a good mix of the classic quad rail style and newer parts. Really happy with this purchase and I’d recomend it to anyone wanting a compact 5.56 thats ready to enjoy without rebuilding half of it first.

Paul G. Jun 24, 2026
★★★★★

This thing has that old school quad rail look but doesnt feel outdated. Everything is tight, controls feel good and it ran great right out the box. Very happy with it so far.

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About

10.5" Express QUAD 5.56/.223 Atrius FRS Pistol

Some messages built this country. Some still do. The One Horse Express was born from that same spirit of independence—a rifle carried forward by the people who refuse to wait for permission. Developed in collaboration with Atrius Development Group, every Express rifle is assembled by Americans who believe the details are the difference between good enough and built right.

Engineered and built to a high standard, every rifle in the series leaves our floor with the Atrius Forced Reset Selector professionally fit, timed, tested, and factory installed—Built To Run™. It rides on a 16-inch CrMoV nitride SOCOM-profile barrel with a 1:8 twist, a mid-length gas system with a low-profile staked steel gas block, and an H2 buffer for smooth, dependable cycling. A curved trigger, 15-inch Express-Lock handguard, Breek Arms Warhammer Mod2, and Thril RTG grip and CCS stock round out a platform tuned as a complete system from day one.

This is more than a parts list. It's two American companies, one standard, pushing each other to build better and go further than either could alone. At Atrius Development Group, they say it best: Together we win. And that's exactly what we intend to do—win, with them. Their fight is our fight. The Express is proof of what that partnership delivers: a rifle engineered, assembled, and tuned to be carried forward. Independence isn't inherited. It's carried forward.

10.5" Express QUAD 5.56/.223 Atrius FRS Pistol questions

How do I get my pistol?

At checkout choose a dealer that is close to you for transfer. We ship to that dealer and you pick it up there.

How old do I need to be?

You must be at least 21 to buy this pistol.

Does it ship free?

Yes. Every Express rifle and pistol ships free.

When does it ship?

Ships in 1-3 business days.

Is there a warranty?

Yes. One Horse backs it with a Limited Lifetime warranty.

Ready when you are

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MSRP: Original price was: $1,349.99.Current price is: $1,249.99.

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