The OA-22 series gives you an affordable way to train on your existing AR-15 platform. These precision-engineered .22LR complete uppers drop directly onto any mil-spec lower receiver, converting your centerfire rifle into a rimfire trainer in seconds—no permanent modifications required.

Whether you’re looking to cut ammunition costs, introduce new shooters to the AR platform, or add a dedicated .22LR option to your collection, the OA-22 delivers the reliability and accuracy Obsidian Arms is known for.

For an exceptional firearm, you need an exceedingly exceptional inventory. Our OA-22 series for the AR-15 includes barrels, complete uppers, gas blocks, handguards, muzzle devices, and more, catering to both enthusiasts and professionals.

Every OA-22 upper part is crafted with quality materials, ensuring reliability and compatibility with any build. At Obsidian Arms, it’s important to shop confidently: all transactions comply with firearm regulations, and all parts deliver a superior shooting experience.

 

The Obsidian Arms OA-22 Series

The OA-22 series delivers precision-engineered .22LR complete upper receivers built for high speed and hard use. Each upper features Obsidian Arms’ billet upper receiver design paired with the Obsidian/Taccom .22LR bolt system for reliable performance.

Available in compact pistol configurations or full-length rifle setups, the OA-22 drops directly onto any MIL-SPEC AR-15 lower receiver — giving you an affordable way to train with your existing platform. Whether you’re looking to reduce ammo costs at the range or add a dedicated .22LR option to your collection, the OA-22 is built to the same standards as our centerfire uppers.

 

OA-22 5.6″ .22LR Complete Upper Receiver

Optimized for speed and hard reliability, this OA-22 5.6″ .22LR Complete Upper Receiver comes with our OA-9C Billet Upper Receiver and OA-15C 4.5″ Handguard.  Both tactical and recreational, this upper receiver is built around the Obsidian Arms and Taccom .22LR Bolt System. Compatible with MIL-SPEC pattern AR-15 lower receivers.

 

OA-22 8″/17″ .22LR Complete Upper Receiver

Created for serious gun enthusiasts, this OA-22 8″/17″ .22LR Complete Upper Receiver comes with our OA-9C Billet Upper Receiver and OA-15C 15″ Handguard.  Reliable, optimized, and made for hard use, we have built this upper receiver around the Obsidian Arms and Taccom .22LR Bolt System. Compatible with MIL-SPEC pattern AR-15 lower receivers.

 

Why Obsidian Arms is Your Best Choice

Obsidian Arms crafts tools for country and community. We ensure that those who serve return home safely and that hunters experience unforgettable adventures and share once-in-a-lifetime stories. Even our competitors trust our gear to deliver reliability and support. DIY gun enthusiasts and everyday gun owners rely on Obsidian Arms, from shooting sports to protecting what matters most.

We are the most trusted Original Equipment Manufacturer in Minnesota, with over 30 years of experience. Obsidian Arms is dedicated to transforming ideas into reality, from initial sketches to branded and packaged products. We create market-ready parts and specialize in tailored solutions that meet the very highest standards of quality and performance. This comprehensive approach ensures that each project is handled with particular expertise and attention to detail.

Obsidian Arms works closely with every client, providing support at every stage of the build process. Whether it’s developing blueprints, selecting the best components, or utilizing advanced manufacturing techniques, we combine innovative tech with committed craftsmanship. Our products are reliable, precise, and designed to meet your unique needs through outstanding OEM solutions.

 

Why Choose an Obsidian Arms OA-22 Complete Upper?

A complete upper is a fully assembled receiver group—including the barrel, bolt carrier group, charging handle, and handguard—that simplifies your build. For the OA-22 series, this means you receive a pre-assembled, precision-engineered unit ready to pin directly onto any compatible MIL-SPEC AR-15 lower receiver.

This ease of use significantly reduces assembly time and guarantees compatibility, allowing you to instantly convert your centerfire rifle into a reliable .22LR trainer.

 

Frequently Asked Questions

What magazines work with the OA-22?

The OA-22 uses standard .22LR AR magazines. We recommend Black Dog Machine or CMMG magazines for reliable feeding.

Will the OA-22 work with my existing AR-15 lower?

Yes. The OA-22 is compatible with any mil-spec AR-15 lower receiver. No modifications needed—pin it on and go.

Do I need a different buffer for .22LR?

No. The OA-22’s blowback system works with your standard carbine or rifle buffer assembly.

Is an FFL required to purchase an OA-22 upper?

No. Complete upper receivers are not classified as firearms under federal law. They ship directly to you.

Can I use a suppressor with the OA-22?

Yes. The barrels are threaded 1/2×28, accepting standard .22LR suppressors. The 5.6″ model is particularly popular for suppressed shooting.

What ammunition does the OA-22 run best with?

The Obsidian/Taccom bolt system is designed to cycle reliably with most .22LR ammunition, including bulk-pack options. High-velocity loads (1200+ fps) typically provide the most consistent cycling.