Over the past five years, Hornady has been enhancing its cartridge lineup by refining and “advancing” existing calibers. These innovations, known as Advanced Rifle Cartridges, push the boundaries of performance and versatility.  During this time, Hornady has relied on Manson Reamers as their trusted provider of Chamber Reamers and Headspace Gauges for initial testing, research, and development. This partnership has thrived, extending support to popular cartridge families like the PRC and ARC series. Below, we take a closer look at these cutting-edge ARC offerings.

338 ARC – (Introduced in 2025)

​Hornady’s introduction of the 338 ARC (Advanced Rifle Cartridge) marks a significant advancement in subsonic ammunition, offering shooters enhanced performance within the AR-15 platform and Manson Reamers is proud to offer 338 ARC Chamber Reamers and Headspace Gauges to support Hornady’s latest ARC addition.

Optimized Performance

Although this is the newest addition to the lineup, it isn’t the first time Hornady has sought a partnership with Manson Reamers. Hornady understands that achieving optimal performance requires a trusted relationship with its tooling provider. The 338 ARC is meticulously designed to ensure consistent pressure, enabling reliable cycling in both supersonic and subsonic configurations. This versatility makes it compatible with various platforms, including AR-15s and micro-bolt action rifles.

Ammunition Options

Hornady offers the 338 ARC in two distinct product lines:

• Hornady BLACK®: Featuring a 175-grain Hollow Point (HP) Match™ bullet, this version is tailored for optimized performance across diverse firearm platforms.
• Subsonic: Equipped with a 307-grain Sub-X® bullet, this load is designed for accuracy and effective terminal performance below the speed of sound. ​

Comparison with Other Cartridges

The 338 ARC offers notable advantages over existing subsonic cartridges. Compared to the 300 Blackout, it delivers 1.5 times more energy, providing greater stopping power. According to Gun Digest this cartridge surpasses the 8.6 Blackout in versatility and performance, fitting seamlessly into standard AR-15 rifles with minimal modifications.

Reloading Essentials

For enthusiasts interested in reloading, Hornady provides a comprehensive suite of 338 ARC components:

• Modified Case (A338A)
• Cartridge Gauge (.338)
• Die Set 2 (.338)
• Full Length Die (.338)
• Seater Die (.338)

These Reloading Essentials and Dies & Accessories ensure precision and consistency for reloaders aiming to get the most out of the cartridge’s potential. ​

Industry Collaboration

The development of the 338 ARC has gathered support from notable firearm manufacturers such as Aero Precision, Brownell’s, and Smith & Wesson, among others.

Ultimately, the 338 ARC by Hornady stands out as a powerful and versatile cartridge, offering enhanced energy and reliable performance for shooters looking for superior subsonic capabilities within the AR-15 platform. ​

​​22 ARC – (Introduced in 2024)

​Hornady’s 22 Advanced Rifle Cartridge (22 ARC) has received widespread recognition, earning the 2024 Ammunition of the Year award by Guns & Ammo. The 22 ARC brings a new level of performance to the AR-15 platform, delivering ballistics comparable to the renowned 22-250 Remington. According to a Guns & Ammo editorial, this innovative cartridge caters to hunters, precision shooters, and those seeking a high-velocity, low-recoil option in both AR-pattern and bolt-action rifles. ​

Design and Performance

The 22 ARC was meticulously engineered to accommodate modern, high-ballistic-coefficient (BC) bullets. By designing the cartridge and chamber simultaneously, Hornady ensures consistent accuracy, optimal velocity spreads, and an exceptional shooting experience. The cartridge’s maximum overall length of 2.260 inches allows seamless integration into standard AR-15 magazines, providing flawless functionality. A 1:7” twist rate optimally stabilizes heavier .22 caliber bullets, enhancing precision.

Ammunition Offerings

Hornady offers the 22 ARC in several configurations to suit various shooting applications:

• 62 gr ELD-VT™ V-Match™: Designed for varmint hunting and target shooting, this load delivers a muzzle velocity of 3,300 fps from a 24-inch test barrel, ensuring flat trajectories and effective performance at extended ranges. ​
• 88 gr ELD® Match: Tailored for precision shooting, this load achieves a muzzle velocity of 2,820 fps, offering high BC for superior accuracy and wind resistance. ​
• 80 gr ELD-X® Precision Hunter®: Optimized for hunting, this load provides controlled expansion and deep penetration, with a muzzle velocity of 3,010 fps, ensuring effective terminal performance on game. ​
• 70 gr CX™ Superformance®: Utilizing progressive propellants, this load increases rifle performance by up to 200 fps without additional chamber pressure, recoil, or muzzle blast, achieving a muzzle velocity of 3,300 fps.
• 75 gr ELD® Match Black™: Part of the Hornady BLACK® line, this versatile load is suitable for various shooting platforms, offering a muzzle velocity of 3,075 fps and consistent performance. ​

Historical Development

The concept of the 22 ARC dates back to 2010, originally dubbed the “.22 Coyote.” Hornady’s Vice President of Sales and Marketing, Neil Davies, envisioned achieving 22-250 performance within the AR-15 platform. Collaborating with Director of Engineering Mitch Mittelstaedt, they selected the 6.5 Grendel as the parent case due to its superior powder capacity. The project gained momentum in 2017 with the rising demand for high-BC bullets, culminating in the development of the 22 ARC. ​

Industry Recognition

Upon receiving the 2024 Ammunition of the Year award from Guns & Ammo, Neil Davies, Hornady Marketing Director stated “This little hotrod is a perfect fit for long-range target shooters and varmint hunters alike. We appreciate the recognition from Guns & Ammo”. The 22 ARC was also recognized as the Best New Ammunition by the National Association of Sporting Good Wholesalers (NASGW) on October 15, 2024. This recognition highlights its exceptional design and performance, solidifying its position in the ammunition market.

Overall, Hornady’s 22 ARC stands out as a versatile and powerful cartridge, offering shooters the benefits of high velocity, low recoil, and compatibility with the AR-15 platform. Its diverse load options and meticulous engineering make it a compelling choice for various shooting disciplines and Manson Reamers now offers a 22 ARC Hornady Rougher and Finisher Reamer as well as the 6.5 Grendel Headspace Gauges that work with these new reamers.

 6 ARC – (Introduced in 2020)

​Hornady’s introduction of the 6mm Advanced Rifle Cartridge (6mm ARC) in 2020 marked a significant advancement in ammunition technology, offering a versatile and efficient solution for shooters seeking high performance from the AR-15 platform.

Design and Performance

The 6mm ARC is engineered to deliver results previously unattainable with the AR-15, achieving an optimal balance of system weight, performance, and shoot ability. It accommodates high-ballistic-coefficient (BC) bullets, ensuring superior accuracy and energy retention over extended ranges. ​

Ammunition Offerings

Hornady provides several factory-loaded options for the 6mm ARC:

• 105 gr BTHP Hornady BLACK®: Designed for versatile use across various shooting applications. ​
• 108 gr ELD® Match: Tailored for precision shooting, offering exceptional accuracy for competitive scenarios. ​
• 103 gr ELD-X® Precision Hunter®: Optimized for hunting, delivering effective terminal performance across practical ranges. ​
• 6mm ARC 80 gr ELD‑VT™ V‑Match™: Designed for varmint hunting with reduced weight out of the nose, making it lighter and yet able to maintain shape drag. Offering rapid expansion, high velocity retention and minimal wind deflection.

Evolution and Origin

The development of the 6mm ARC originated from military needs, driven by changing battlefield tactics. The 5.56mm cartridge proved ineffective beyond 500-600 meters, while the 7.62mm offered greater range but introduced challenges due to its heavier system. The goal was to create a cartridge that retained the weight and size advantages of the AR-15 platform while delivering the external ballistics and terminal performance of the 7.62mm or .308. The result, the 6mm ARC, is a solution designed to equip modern warfighters and law enforcement with an effective round for both close-quarters and long-range engagements.

Compatibility and Versatility

The 6mm ARC is compatible with AR-15 platforms and short or micro-action bolt guns, making it suitable for applications ranging from personal defense to match shooting and hunting. Its design allows for efficient performance with less recoil compared to larger cartridges, enabling shooters to make rapid adjustments and self-spot changes. ​

Industry Adoption

The introduction of the 6mm ARC has been met with enthusiasm from various firearm manufacturers, with companies such as Barrett, Brownell’s and Savage producing rifles chambered for this cartridge. ​

All in all, the 6mm ARC by Hornady represents a significant innovation in rifle ammunition, providing shooters with a cartridge that balances power, precision, and versatility within the AR-15 platform. Once again Manson Reamers has your tooling needs covered with this cartridge by offering 6mm ARC Reamers and Headspace Gauges.

Additional supporters of these new cutting-edge cartridges include, but are not limited to:

• Ballistic Advantage – 338 ARC barrels, 22 ARC barrels, and 6mm ARC barrels
•  ​Faxon Firearms – 338 ARC barrels, 22 ARC barrels, and 6mm ARC barrels
• CMC Triggers – AR-15 trigger options and various accessories
•  CMMG – Magazines, barrels, and various other components for 338 ARC, 22 ARC and the 6mm ARC

A big thanks to Hornady for trusting Manson Reamers to develop their cartridges with us. Visit Manson Reamers today for all your Advanced Rifle Cartridge (ARC) tooling needs!