Hornady Introduces the 6mm ARC, or Advanced Rifle Cartridge

Hornady just officially announced the 6mm ARC, or Advanced Rifle Cartridge, for the AR-15 platform. The new cartridge is similar to a number of wildcat loads based on 6.5 Grendel necked down to 6mm.

While some people are saying that this cartridge is to 6.5 Grendel what .224 Valkyrie is to 6.8 SPC, others are saying this is what 6.5 Grendel should have been in the first place.

SEE ALSO: Barret Firearms Awarded DOD Contract for REC7 Rifles in 6mm ARC

“Tested, selected and fielded by a specialized group within the U.S. Department of Defense for its multipurpose combat rifle program, the versatile 6mm ARC does much of what larger cartridges can and everything that smaller cartridges can’t,” said Hornady. “Designed to meet the needs of the world’s toughest critics, the 6mm ARC utilizes efficient, high-BC bullets to deliver unprecedented performance from the AR-15 platform.”

Hornady’s three initial loads range from 103 to 108 grains. (Photo: Hornady)

“Commercial 6mm ARC offerings will feature bullets selected to deliver ideal performance for hunting, match shooting and personal protection applications,” they said. Hornady is launching with two loads, a 105-grain hollow point for hunting and self-defense and a 108-grain low-drag round for match shooters.

Rumors that Hornady was working on a 6mm cartridge started making the rounds earlier this year when a mystery 6mm ammunition specification was accepted by SAAMI, the Sporting Arms and Ammunition Manufacturers’ Institute, the standard-keeper for most ammo in America.

Hornady’s 6mm ARC pushes 103- to 108-grain bullets at around 2,750 feet per second at the muzzle out of a 24-inch barrel. That works out to over 1,900 feet per second at 500 yards and it remains supersonic out past 1,100 yards.

One thing it does have in common with .224 Valkyrie is that Hornady went the distance and lined up a lot of industry support for their new cartridge. Not only does Hornady have two loads ready at launch with a third due later this year, they have components, reloading dies and market support from a large number of manufacturers right now.

Lantac USA is one of the companies offering complete rifles chambered for the new 6mm ARC. (Photo: Lantac)

Manufacturers working with Hornady include APF Armory, Barrett, Brownells, Christensen Arms, CMC Triggers, CMMG, Faxon Firearms, G.A. Precision, Geissele Automatics, Howa USA, Lantac USA, O.F Mossberg & Sons, NEMO Arms, Noveske, Odin Works, Proof Research, Radical Firearms, Uintah Precision and Wilson Combat.

Not only are the companies supplying parts including barrels but many of them offer complete rifles.

Existing 6.5 Grendel shooters only need a 6mm ARC barrel to try the new cartridge. Everything else is compatible with 6.5 Grendel including the bolts and magazines.

See Also: Hornady’s NEW 6mm ARC & Odin Work’s Barrels–First Field Tests

Because 6mm ARC is based on some well-established wildcat rounds, reloaders will be able to quickly adapt known handloads to the new cartridge.

Hornady’s 6mm ARC is meant for shooting out to and even a little beyond 1,000 yards. It’s a match cartridge that can also double as a hunting round for small and medium game where the projectiles are permitted. Hornady’s third cartridge, due this fall, is a hunting-specific 103-grain round.

And of course, even though this was developed for AR-15s and similar rifles, that doesn’t mean it’s limited to AR-style guns. There are plenty of micro-action rifles and other firearms that will gladly support the new cartridge.

With the amount of support for the new 6mm ARC this cartridge looks like it will be more than just a fad.

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About the author: Max Slowik is a writer with over a dozen years of experience and is a lifelong shooter. He has unwavering support for the Second Amendment and the human right to self-defense. Like Thomas Paine, he’s a journalist by profession and a propagandist by inclination.

{ 30 comments… add one }
  • kevin R. June 8, 2020, 5:59 pm

    Been shooting 6.5 Grendel for 15+ years in the AR platforms. Haven’t found a Grendel magazine yet that functions flawlessly with more than 10rds in it. The magazine is what will kill it in the AR platform unless somebody makes a different upper and lower with a wider magazine. The grendel/6.8 magazine has to much curve to stack the rounds properly along with to narrow of a width.

  • TRAIL June 8, 2020, 2:20 pm

    Well this is interesting. I thought the 224 Valkrie should have been the 243 Valkrie. No doubt the 224Val outflys the 223 Rem. The 6 mm Arc should out perform the 6.5 grendal too. But why all the sidestepping to get to an intermediate 6mm cartridge for the AR platform? Im no bullet engineer so why not just make a 6mmx45 Nato and be done with it? Just seems the easiest thing to do and the least expensive to use what we got. Then the DOD and the rest of us would only have to change out our barrels. There is some cheap steel wolf 6.5mm GREN out there but premium ammo cost at least dollar a round or more. In some cases, even more than 6.5 mm creedmor which is a bigger cartridge. No doubt the 6mm ARC will be at least a dollar a round making it too expensive for casual plinking. Seems like a 6x45mmNato would easier to produce and cheaper to shoot. Making it more likely to catch on.

  • skip roos June 8, 2020, 1:00 pm

    Duplicates the 6mm Lee Navy, smaller modern package, etc.

  • manimal June 8, 2020, 12:17 pm

    more interested in the 6.8mm hybrid round that Sig delivered to the US Army along with the next generation squad weapons. Whatever the military switches to on AR platforms will be what we’ll end up buying at a decent price like with do with 5.56 today.

  • Mongo Go Bang June 8, 2020, 11:14 am

    Well this is going to go nowhere in the long term. It’s basically an improved 6mm/223 round from the past. The 220 Russian case is a deal killer for an AR15 as it requires a new bolt head, as well as a new barrel and magazine. In contrast, the most successful commercial alternative to the 5.56 round is 300 BLK, which use the same magazines, bolt head and requires only a barrel change out.

    The majority of shooters engage paper targets at 200 yards or less, fire around 200 rounds a year and statistically ZERO of them, have ever shot a target at 1,000 yards.

    As far as a potential military round, not going to happen. Don’t care how many Gucci Units get to play with this, its going to be looked at and played with and shelved. Serious rifle/carbine ammo will be found in machine gun belts, first, as machine guns do the killing with riflemen in support, mostly. Not going to penetrate Level 4 body armor, so it has no usefulness over the current 5.56.

    For the Varmint/Benchrest crowd, the 6mm ARC with will be another accurate round based on the 220 Russian case. Enjoy.

  • lloyd myers June 8, 2020, 8:42 am

    This is one of the most efficient magazine length round that can safely be fired in the AR platform. The fact that you can magazine load 105-110 class 6mm bullets long gives it the advantage. High power shooters have been shooting this variant for many years.

  • GaryGary June 8, 2020, 8:32 am

    New flavor of the year ?

    I must admit the “new” cartridge deluge has really slowed down until now. This wildcat round will find a few followers but I’m sure that will be about it ? Until such a time when a accurate 110-120 grain round out of a 16″ barrel stepping out at 3100 fps without burning out the barrel comes along don’t expect any rush for new cartridges ?

  • Quinton June 8, 2020, 7:54 am

    It would appear we already have this cartridge. It is called the 6mm PPC. I wish Hornady would quit making new cartridges and use the ones we already have.

  • Tye June 8, 2020, 7:24 am

    I’ve already been shooting this cartridge for over 10yrs. Looking at the SAAMI drawing IT IS a 6mm grendel. It shows me that someone at Hornady actually went to a match somewhere. Should be called the 6mm grendel or the 6mm NN for Nothing New….

  • Frank S. June 8, 2020, 7:15 am

    A big, well known bullet manufacturer rolling this out with good support before it’s announced…. that might be the winning ticket. If they had just got a major manufacturer to jump on board right away (like Remington or Ruger) it would have been even better, but they do have some good manufacturers and suppliers working with them. Mossberg is more known for shotguns, but have been building rifles (some made in Turkey… not sure if Mossberg design or imported Turkish designs) for quite a while, mostly .22s in the 60s. Not the biggest name in rifles, but a good selection now, and pretty well known.

    Is it better than the 6.5 Grendel? Looks like it’s just slightly different to me. Not enough difference to switch cartridges, but if you’re not heavily invested in the Grendel or 300 Blackout it’s worth a look. depends on what you want out of it, and if it will suit that/those needs. Looks like Hornady thought a lot about that, making bullets and loads that will provide a wide range of needs.

  • Will Drider June 6, 2020, 2:52 pm

    2750FPS From a 24 inch barrel and designed for AR15 configurations. If we review the common AR configuration barrel length: it falls a hair over 16 inches. Even though DoD is buying some ARC rifles from Barret it is pure folly to think people will jump in mass to the cartridge like what happened with the last FBI change to the 9mm. A new Cartridge is great, the mor the merrier but it will have the same lacluster sales as the Grendel and many other “cartridges of the week”. VMMV

  • Chee June 5, 2020, 5:51 pm

    How many caliber configurations do we need? We already have 50 too many. Wouldn’t the money be better spent in improving what we have. I got 18 to inventory now and 300 blackout been armed down my wallet.

  • Dan June 5, 2020, 5:11 pm

    No thanks. I’ll stick with my Grendel. This may find it’s place where it’s needed.
    Hornady says 2650fps for a 108gr bullet out of a 20″ barrel.
    I’m sending a 123gr at 2500fps out of a 20″ barrel in my Grendel. It was possible to have more velocity but the groups dropped off, in the testing of my proof barrel.

    • Give Me Freedom June 8, 2020, 6:45 am

      If the United States military does not adopt the 6 millimeter Advanced Rifle Cartridge I would also prefer 6.5 x 39 Grendel. Likely it will not pick the 6 millimeter round. The two most popular major alternatives to 5.56 x 45 that have come out for the AR-15 are .300 Blackout and 6.5 x 39 Grendel in my opinion. I like 6.8 x 43 Special Purpose Cartridge but it’s popularity seems to not be what Blackout and Grendel are from what I see in 2020.

  • Dave Salas June 5, 2020, 10:28 am

    Remembered how unpopular the 6mm caliber was when it was first introduced way back when. The popularity all seem to go towards the 243 . Not much different really other than the 6mm Remington seem to carry a tat more powder in the 100 gr.
    I purchased a Remington youth model 7 for my son 30 years ago. @ times it could be difficult finding factory loads for that rifle. That’s when I started stocking up when I came across them.
    I’m quite please that Hornady is going to have these available, if they are not out already.
    I’m understanding that these ARC rounds will chamber problem free into the Remington Model Seven 6mm ?

    • Tim Esplin June 5, 2020, 1:51 pm

      The 6mm failed early because of rifling twist, no stabilizing hunting weight bullets.

    • JRT June 8, 2020, 8:14 am

      “I’m understanding that these ARC rounds will chamber problem free into the Remington Model Seven 6mm ?”

      NO! Absolutely not! 6mm Remington and 6mm ARC cartridges have nothing in common other than bullet diameter. Please don’t try this.

  • Awesome Bill from Dawsonville June 5, 2020, 10:21 am

    Looks like a hell of a round. That being said we still don’t know how it performs from a 14.5″ barrel as opposed to a 24″ test barrel. How many rounds will fit in a GI mag?

    There have been a ton of rounds (WSM anyone?) that have been commercial flops as of late and many of those went out claiming to be the next replacement for the 5.56. They will always have their cult followings but I don’t want to be an early innovator and get stuck with another 300WSM or 45GAP.

    • Max Slowik June 5, 2020, 8:47 pm

      24 or 25 from what we’ve seen so far. So you do give up a little. But for supersonic out to 1150? Decent trade.

      I’ve seen FPS numbers for 18-inch barrels at 2,600 so probably around 25 FPS per inch is a decent starting point? Real-world testing will bear out numbers.

      I know it’s my job to be excited about new products, but…I’m really excited about this.

  • Tommygun851 June 5, 2020, 9:23 am

    Working with the limits of the AR15 platform, to get the most out of a cartridge that works in the action without a large heavy bullet, start with the largest case capacity (458 Socom or 50 Beowulf) and neck it down to a reasonable diameter. Something large enough for big game but small enough for a reasonably light recoil. Say in the 6.5mm to 30 cal. You will have a cartridge like a short mag or super short mag having the power of a 308 Win capable of taking any large game in North American.
    That is the next cartridge that I want for my AR! Not some one just stick a different size bullet in and give it a new name!!!!

    • George June 5, 2020, 2:00 pm

      Look up the .30 Remington AR. I bought one years ago and when Remington didn’t promote it like they should, I bought all of the ammunition and brass I could find, plus loading dies. My favorite load, straight from a Hornady reloading manual, pushes a 160 gr FTX bullet to just under 2600 fps. (The FTX bullet is intended for the .308 Marlin round).

      • Tommygun851 June 6, 2020, 11:15 am

        George, thanks for the response! Now, why did the 30 Rem AR not take off just for the hunting performance alone? Not backed by the right bullet/gun manufacturers? I will definitely take a close look at this cartridge (given availability) for my next upper! Just imagine dropping the seemingly ideal 6.5 bullet in that case and getting a couple of hundred more FPS out of it! Again, thanks!

        • PacosMojo June 8, 2020, 7:34 am

          The 30AR is a great cartridge, but they’re a lot of “howevers”. First, Remington was the only major ammunition provider that manufactured the cartridge. Even then, I only think they produced two offerings. And then there’s the proprietary nature of the rifle itself. Since the 30AR operates at a much higher pressure than other AR15 chambered cartridges, Remington designed a CUSTOM bolt with a significantly a thicker support rim, which will only mate with a CUSTOM AR15 barrel extension (AR10/308 won’t work either). The barrel nut is also CUSTOM, and therefore, you need a CUSTOM factory upper receiver and CUSTOM handguard. I own a Remington 30AR, and believe it’s the best hunting cartridge ever designed for the AR15 platform. But it’s an esoteric chambering, and I doubt any other manufacturer is chomping at the bit to resurrect this ugly duck anytime soon.

          • Sandsock June 19, 2020, 10:01 am

            The other factor was the increasing availability and affordability of AR10 type rifles and components because people if given a choice went for the established cartridge for about the same amount of money

  • Mike in a Truck June 5, 2020, 8:49 am

    Yawwwwwn. What will this new cartridge do better than my 243 Winchester that I’ve had since ’76? Oh wait, it’s not cool,new,hip and millions cant be spent in development cause it’s already been done. Truth is, in combat I preferred an area weapon.I chose the M79 for maximum handheld lethality with secondary missile hazards.Later an M16A1/ M203 was my choice. What is needed is a magazine fed 30mm grenade launcher based on the AR pattern with a selection of munitions including “smart munitions”. But hey what do I know. Dont run anything anymore cept this truck.

    • JCitizen June 8, 2020, 12:39 pm

      I know what you mean – I loved my M-203, and didn’t even mind humping the ammo vest in the mountains. I just had that much more confidence, that it was a great motivator! They have been extensively trying for something semi-automatic in the 20 to 30 mm grenade launcher range, but nothing practical has come of it yet. I guess we’ll just have to hope DARPA takes a tip from the gamers to make a good design.

  • Tim June 5, 2020, 7:42 am

    I would be more interested in knowing what the muzzle velocity is from a 16″, 18″ or even a 20″ barrel. Giving the velocity based on a 24″ barrel isn’t very meaningful for most AR users.

    • FAL Phil June 5, 2020, 8:03 am

      Go to Hornady’s website. There is an in-depth interview with one of their design engineers where he talks about shorter barrels.

  • Leighton Cavendish June 5, 2020, 7:18 am

    When will we see Hornady 5.7X28?????

    • bob w June 5, 2020, 2:34 pm

      Hell yeah!

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