The Hornady 6mm ARC (Advanced Rifle Cartridge) is an intermediate cartridge released in 2020 to increase the power of the AR-15 platform.
Developed for the Department of Defense (DoD) and its multipurpose combat rifle program, the 6mm ARC can achieve ballistic results similar to larger calibers like the 308 Winchester but without the shortcomings of smaller rounds like the 5.56 NATO.
But should you invest in a 6mm ARC conversion for your favorite AR-15 carbine, or would you be better served looking at other calibers like the 224 Valkyrie, 300 AAC Blackout, or 6.5 Grendel?
In this 6mm ARC ammo review, we’ll take a hard look at this new Hornady cartridge, see if all the hype is warranted, and help you decide if investing in the 6mm ARC is right for you and your shooting needs.
The Hornady 6mm Advanced Rifle Cartridge (ARC) was released in 2020 as part of a bid for the Department of Defense’s multipurpose combat rifle program. This program was established to replace the aging M16 and M4 Carbines currently in service with the U.S. military.
Although the contract eventually was won by Sig Sauer and their new cartridge, the 277 SIG Fury, the 6mm ARC (6ARC for short) is still an incredibly innovative and effective intermediate cartridge that greatly enhances the capabilities of the AR-15 platform.
As stated on Hornady’s website:
“The 6mm ARC does what much larger cartridges can and everything that smaller cartridges can’t.”
Developed using the 6.5 Grendel as a parent cartridge, the 6mm ARC fires 0.243” diameter projectiles. These are the same 6mm bullets used in the 243 Winchester and 6mm Creedmoor rounds. This allows the 6mm ARC cartridge to deliver similar long-range ballistics to larger rounds but in a smaller, lightweight package.
Hornady’s goal was to create a cartridge that had superior muzzle velocity compared to heavier rounds like the Grendel or 6.8 SPC but still fire incredibly high ballistic coefficient bullets for long-range precision rifle shooting (PRS).
In short, Hornady achieved its goal, and initial long-range shooting tests on the 6mm ARC were very positive. Most shooters report being able to achieve MOA-level accuracy or better while using factory loads, which is a real testament to Hornady’s design and attention to quality control.
I find the Hornady 6mm ARC to be an extremely interesting cartridge concept, and I considered it for my long-range AR-15 precision rifle build. Although I eventually settled on the 6.5 Grendel due to ammo availability, the 6mm ARC has many qualities that I like in a long-range shooting cartridge.
First off is the high ballistic coefficient of the 6mm bullets Hornady selected. From their three factory loads, the BC ranges between 0.512 and 0.536. To put that in perspective, a Hornady 168-grain ELD-M 308 Winchester bullet has a BC of 0.523.
Compare that to an average BC of around 0.22 for 5.56 NATO ammo, and you can see why the 6mm ARC is an excellent choice for long-range shooting. This speaks volumes to the design of 6mm bullets, as their long and sleek profile is exceptional at resisting wind drift which is important for long-range shots.
Another aspect I like about the 6mm ARC is that it shares the same bolt and magazines as the 6.5 Grendel. This makes converting your standard AR-15 carbine as simple as a barrel, magazine, and bolt swap. Or if you own a Grendel already, your mags and bolt-carrier group can serve double duty.
Lastly, the 6mm ARC offers shooters ballistics like a 308 Winchester without having to upgrade to the AR-10 platform. This represents massive weight savings. And if you plan on taking your rifle out into the field, then you’ll quickly understand the benefit of packing an AR-15 compared to an AR-10.
From a handloading standpoint, I find the 6mm ARC extremely interesting, as Hornady published two sets of reloading data for the round. This is due to the limitations of gas block design on an AR-15 compared to a bolt-action rifle. Hornady’s manual was very explicit about which load was acceptable for each rifle, as the bolt-action loads have a maximum listed chamber pressure of 62,000 psi compared to 52,000 psi for gas guns.
However, if you do want a bolt gun for the 6mm ARC, there are a few options available from Howa, Savage, Mossberg, Christensen, and Proof Research. Full AR rifles and uppers can be purchased from high-end AR manufacturers like Geissele, CMMG, Barrett, Odin Works, Wilson Combat, and Noveske.
Although the 6mm ARC has been adopted by multiple firearms manufacturers, some of the big names like Ruger, Winchester, and Remington have not opted to add the 6ARC to their roster just yet. Furthermore, more budget-friendly AR-15 manufacturers like Aero Precision, Smith & Wesson, and Springfield Armory have also not adopted the cartridge to their rifle lines just yet.
Overall, I like the 6mm ARC. It is an excellent upgrade to the AR-15 platform that gives it better terminal performance at long range than a 5.56 NATO/223 Remington could ever dream of. My only concern is the lack of ammo availability, putting the Hornady 6mm ARC at a solid 4.5/5 stars based on my assessment.
If you want to turn your AR-15 carbine into a tack driver but want something with a little more oomph than a 5.56 NATO or 224 Valkyrie, then the 6mm ARC is a perfect choice as it is designed for long-range shooting. Most shooters report achieving sub-MOA groups with boring regularity with their 6mm ARC rifles.
The 6mm bullet offers shooters high ballistic coefficients that are ideal for long-range shooting, making the 6mm ARC a great choice for varmint and medium game hunters alike. Capable of taking down prairie dogs at range while still having the kinetic energy needed for whitetail, mule deer, and pronghorn, the 6mm ARC offers hunters a lot of flexibility with a single rifle cartridge.
The 6ARC also has about 50% of the felt recoil of a 308 Winchester while still having less recoil than a 7.62x39 round, making it incredibly pleasant to shoot for long periods of time.
Perhaps the biggest disadvantage of the 6mm ARC is the lack of new factory ammo available for the cartridge. At the time of writing, Hornady is the only company that makes factory ammo for the 6mm ARC. This means that unless you have a deep ammo budget, you’ll need to resort to handloading to keep your 6mm ARC rifles properly fed.
Going together with the necessity for reloading, only Hornady and Starline produce new brass for the cartridge currently. This means that the availability of once-fired or factory-new brass will be extremely low.
Obviously, being limited to a 2.26” overall length also somewhat limits the capabilities of the 6mm ARC, and it will never achieve ballistic performance similar to the 300 Win Mag or the 6.5 PRC. However, Hornady took every bit of that overall length and pushed it to the outer limits to make the 6mm bullet shine.
As much as we love ammo, we understand that no manufacturer is perfect. Here are some of the pros and cons of Hornady 6mm ARC ammunition you should be aware of.
Below you’ll see a detailed spec chart for the 6mm ARC.
At the time of writing, there are only three factory loads available for the 6mm ARC, and all three are produced by Hornady. Let’s take a look at each load.
Hornady Black ammo is specifically designed for gas guns like the AR-15. No matter your gas system, no matter if you shoot with a suppressor or not, Hornady Black is designed to run smoothly in the rifles Americans love the most.
Loaded with a 105-grain BTHP (boat tail hollow point), this 6mm ARC load is great for shooting a precision rifle (PRS) match or just for a fun day of plinking at the range. Recommended for a 1:8 twist rate barrel, this 6mm load comes out screaming with a muzzle velocity of 2,750 fps. Please note that muzzle velocity will vary based on your barrel length.
However, if you’re looking for an awesome do-all cartridge, then Hornady Black is what you should be adding to your shopping cart.
If you need pin-point precision and accuracy, then look no further than Hornady Match ammo. Carefully match with the ideal powder, case, and bullet, Hornady Match ammo is highly regarded by shooters who enjoy shooting out to and beyond 1,000 yards.
Hornady Match 6mm ARC ammo is no exception, and the 108-grain ELD-M is an excellent choice if you want to shoot sub-MOA groups with boring regularity. With a ballistic coefficient of 0.536, this ammo is perfectly at home for long-range shooting, where wind drift becomes a major issue. With a muzzle velocity of 2,750 fps, the 108 gr ELD-M has an exceptionally flat trajectory to keep you on target at longer distances.
As the official ammo of the Precision Rifle Series, Hornady Match ammo is an excellent choice for any shooting competition on your schedule or if you simply just enjoy boring out the X-ring at your local range on the weekend.
If you’re looking to put venison in the freezer or rid your property of varmints this fall, then look no further than Hornady Precision Hunter ammo.
Loaded with the deadly 103-grain ELD-X bullet, this projectile offers match-grade precision with devastating terminal expansion. The Heat Shield tip initiates expansion by diving into the lead core of the bullet, while the InterLock ring keeps the jacket firmly attached to the core for maximum weight retention.
With a muzzle velocity of 2,800 fps, Hornady Precision Hunter 103 gr ELD-X 6mm ARC ammo can easily drop a whitetail in its track out to 500 yards or pop a coyote out to 900 yards.
Below we’ve compiled a ballistics table for all three different variations of Hornady 6mm ARC ammunition currently available on the market. Please note that muzzle velocities were calculated using a 24” barrel length.
Hornady 6mm ARC Ammo Review: Make Your AR-15 a Tack Driver originally appeared in The Resistance Library at Ammo.com.