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

The 6mm ARC is a brand new cartridge that Hornady designed to fit into a standard AR-15. ARC stands for “Advanced Rifle Cartridge.” The caliber is 6mm or .243. The cartridge is specifically designed to maximize performance in AR-15s with barrels between 12 and 24 inches. 

If you have an AR-15 all you need to convert over is a new barrel, bolt head, and magazine. 

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

Currently, the most popular selling long-range cartridge in America is Hornady’s 6.5 Creedmoor. Because of how Hornady designed the cartridge and chamber, the 6.5 Creedmoor is exceptionally accurate as long as the rifle manufacturer follows the chamber blueprints that Hornady designed, which most do. Unfortunately, 6.5 Creedmoor is too big to fit into America’s rifle, the AR-15. 

So, Hornady has stepped up and has done the same thing in designing the 6mm ARC that they did in designing the 6.5 Creedmoor. They designed the chamber and cartridge upfront to maximize efficiency and long-range accuracy.  It’s optimized to shoot heavy bullets with high BCs. Hornady recommends a fast 1-7.5 twist barrel to stabilize the heavier bullets. 


ODIN Works 18 inch 6mm ARC.

To test the 6mm ARC we installed ODIN Works 6mm ARC stainless steel barrels into the upper receivers. We tested an 18-inch barrel and a 21-inch barrel. The barrels use a rifle length plus (+) 2-inch gas system. We had an ODIN Works tunable gas block on the 18-inch barrel and an ODIN Works adjustable gas block on the 21-inch barrel. We were extremely limited on ammo so we shot one group out of each gun to get a rough zero and chronograph. Based on what I’ve seen thus far and considering that we did no barrel break-in they shot darn good!  (We’ll get more ammo and do a complete review in the near future.)

ODIN Works 21 inch 6mm ARC.

Using the 21-inch barreled rifle, I went 8 for 8 on a 12-inch-round plate at 708 yards in about 20 seconds with wind. Watch the video to see the recoil or lack thereof, actually.

ODIN Works will be initially offering the barrels in the following configurations:

  • 18 inch with tunable gas block and gas tube
  • 18 inch with tunable gas block, gas tube, and bolt
  • 21 Inch with adjustable gas block and gas tube
  • 21 Inch with adjustable gas block, gas tube and bolt

Odin will also be offering complete uppers ready to pin onto an AR lower for about $950. 

Visit ODIN Works for more information on barrels, bolts, uppers, and magazines for the 6mm ARC. 


Hornady is advertising that their 6mm ARC with 108-grain ELD-M ammunition will go 2,750 fps out of a 24-inch barreled rifle. We chronographed that load at the range using a Labradar chrono out of the 21-inch and 18-inch ARs and got average velocities that were 2,680 and 2,616 which is directly in line with what Hornady is advertising. 

If you do the math there are three inches of barrel difference and 64 fps difference in velocity between the 21-inch and 18-inch barrels. That works out to 21.33 fps per inch of barrel. Both barrels were made by ODIN Works and were brand new. 

Add 64 fps to the velocity from the 21-inch barrel to calculate about what you’d get from a 24-inch barrel and you get 2,744 fps velocity which essentially mirrors with what Hornady is advertising. It’s refreshing to have a company not overinflate their velocity numbers. 


Based on those velocities and a .536 G1 BC the 6mm ARC should equal or slightly outperform the .308 Winchester with the same length barrel to beyond 1,000 yards in both drop and wind drift. 

It’s going to trounce all other commercially (non-wildcat) available cartridges that fit in a standard AR-15 at medium to long-range including the 223 Rem, 5.56mm NATO, .224 Valkryie, 6.5 Grendel, 6.8mm RSPC, and .300 BLK. 

In fact, at my elevation of 2,200 ft, the 6mm ARC would stay supersonic to 1,400 yards. That’s pretty incredible out of a 24 inch barreled AR-15. 


Recoil is minimal. Very similar to a 556. 

Because recoil is minimal it’s easy to spot your own shots. The heavy 6mm bullets make a better splash than 224 caliber bullets and they hit harder. 

Barrel life should be excellent. It’s an extremely efficient cartridge. It’s not burning much powder.

This cartridge might be the perfect, zero recoil hunting caliber for small game up to deer. Hornady says they will have a Hunting ELD-X load available for this Fall.

For a minimal investment in a bolt, barrel, and magazine, the 6mm ARC should allow shooters that already own an AR-15 to upgrade and turn their AR-15 into a capable 1,000-yard rifle. 

Visit Hornady to learn more

Visit ODIN Works to learn more 

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About the author: True Pearce is the Managing Editor at GunsAmerica. He’s a competitive shooter, hunter, instructor & attorney. You can see and follow his adventures on Instagram. @true1911 https://www.instagram.com/true1911/

{ 19 comments… add one }
  • James Murphy April 22, 2021, 11:04 pm

    I bought a Shaw 18″ barrel for my 6ARC build and it has been a “HAMMER”!! I had problems with it at first because I was using a can during my load development. I had made all of my brass from 6.5 Grendel brass that I had found on the internet. I started off using Hornady’s load data and went with Varget since I had some and was using the 80+gr bullets. I was getting 5 shot groups in the .4 to .5 range but when I went to reload my brass I had developed the “Grendel Belt”!! My loads were to hot!! I also experienced brass “Tearing” from my can. Once Hodgdon’s reloading data came out I found out they were a full grain to a grain an a half below what Hornady’s data was saying was max load.
    I tired down loading the Varget but my accuracy went to hell. I then switched to CFE and LVR. I could get back to the velocities that I had with Varget but I didn’t get the pressure that I had before. I also played with the adjustment on the gas block after I settled on a bullet weight. I really like the ARC it is a sweet round to shoot and you can really reach out and touch something with it. I shot the 87VMAX out to 800yds to get some data on it. I used 3 shot groups since I was just getting data for dials and all of my groups were .5 MOA or under for the 3 shots to 800yds. I personally feel it is a round that is here to stay.

  • Jim Meier June 15, 2020, 5:42 pm

    I have had a 6mm DTI for many years and it is a great varmint cartridge and can be used effectively for up to deer. Very low recoil 58gr VMax 3400 fps with no signs of pressue. You can see the p-dog hit in the scope due to lack of recoil, bucks wind way better than 223. So why do I care of Hornady makes this? Because any time they do i can get a new AR chambering without spending $225 for a set of custom dies and forming brass, that money saved goes towards a new upper. Bring on the new chamberings.
    I love the idea and I have AR15’s in 17, 204, 223, 6mm, 25, 6.5 and AR10’s in 257DGR, 6.5, 308.

  • Meridian June 14, 2020, 11:03 am

    The new 300BLK, same as the old 300BLK, except you have to buy a new bolt and mags in addition to a barrel and can’t shoot subs.

    • FAL Phil June 15, 2020, 11:09 am

      Uh, no.

  • Confused June 13, 2020, 11:50 am

    So there’s two rifles and a bunch of ammo in pictures from an article that’s titled “first field tests” and no one has asked “where’s the target pics so we can see the grouping?” So I’ll do it…. it’s a field test article??? Where’s the grouping data? You took all that stuff out in “the wild” and didn’t shoot it?? Or didn’t it perform as well as expected? Not allowed to say? Makes no sense at all they’re not showing accuracy unless…..I smell another 224 Valkyrie.

  • NeoBlackdog June 12, 2020, 9:15 am

    Oh look! They re-invented the .243 WSSM!

    • DJR June 13, 2020, 11:06 pm

      Yes, but it will be around because it is better designed and not created to try and save a run away train with no engineer. The demise of Winchester and it’s short magnums….. This cartridge will last and flourish.

  • Tye June 12, 2020, 8:20 am

    I’ve been shooting this “NEW” cartridge for 10yrs……it’s a 6mm grendel go look at the Sammi drawing. So after a decade someone at Hornady went to a prs match. I guess they learned they’re lesson from the Valkyrie flop. So they looked at the the most popular wildcat

  • William ORR June 11, 2020, 12:01 am

    I shoot nearly every day.I shoot a lot of different calibers too.My favorite in AR15 is my 6.5 Grendel with a stainless 24″ spiral fluted barrel and its a sure enough tack driver. It was also the 1st AR15 I built a few years ago..I didn’t know anything about them..I had hunted all my life with a 270 and 7mm Rem Mag. Killed about everything in North America.
    Now The 6.5 Grendel I built was built with chjeap parts..A cheap $130.00 Bear Creek Arsenal Barrel and PSA upper & Lower parts.I did splurge and get a nice BCG with DLC coating and Its been great. I guess I just got lucky..A barrel is either Accurate or its not..Mine is..Dumb Blind Luck Id say.But it is what is is.
    The 6mmARC is supposed to out do the 6.5 Grendel on paper.But until more ammo is readily available it just cant get 5 stars..The 300 B.O. was supposed to be the one,,,,then the 6.8 SPC II the slickest thing since sliced bread..So we all know how that’s turned out..And the Hornady is raving about the 6mmARC and a 24 inch barrel..How many soldiers do you see packing around a AR15 with a 24 inch barrel…NONE so how much better will it be on the battle field with a 16 inch barrel??? Time will tell if its really better than the 6.8 the military is going to or if it can really top the 6.5 Grendel in a 16 inch barrel…Is it a nice cartridge?? Yes..Will I buy or build one? Yes..Ive got about every caliber so whats one more..We always have room for one more gun..Thanks yall.I hope I did not bore anyone with this long rant

    • Bob June 13, 2020, 11:32 am

      18″ barrel is what is in trials for this caliber, I hope you subscribe to different site’s, you would know this by now

  • martianone June 9, 2020, 4:18 am

    Find it interesting….
    6.5 mm cartridges are all the rage now,
    Not much difference in performance from a famous Swedish 6.5 from over a 100 years ago.
    Or a small cased 300 blk, lauded with great performance- however less effective than 30-30.
    Now we have another “new” 6 mm cartridge, similar in performance to 6 mm Ppc of 1975.
    Happy with my historic cartridges, thanks !

    • tcboomert June 12, 2020, 9:44 pm

      The 6mm ARC, the 6.5 Grendel, etc…were designed arond the AR-15. Now go ahead and chamber your 30-30 or 6.5 Swedish in an AR-15 see what your results are. We are talking about AR-15 calibers are we not? Helloooo McFlyyyyy….

  • Give Me Freedom June 6, 2020, 7:38 pm

    If the military does not adopt this 6 millimeter Advanced Rifle Cartridge I would not touch it. .308 Winchester is very effective out to 600 yards and beyond and very common.

    In my opinion I think the military will go with a 6.5 to 6.8 millimeter caliber cartridge as it has better terminal ballistics.

    • Big Al 45 June 12, 2020, 10:37 am

      Apples and oranges.
      Ever shoot Prairie Dogs with a .308?
      Sure, you can, and if that’s all ya got, more power to ya, but I much prefer the 6’s for that endeavor.
      Yote’s too, .308 is overkill.
      I think the idea here is an accurate round with good downrange energy retention that fits the AR Platform.
      It seems that slipped by a bunch of folk in this comment section.

    • FAL Phil June 15, 2020, 11:13 am

      What is not in the article is that the US military worked with Hornady to develop this cartridge. You can find that out on the Hornady website.

      If all you shoot are US military cartridges, I feel very sorry for you. That’s like having a diet that consists of only ramen noodles.

  • BMWKS June 5, 2020, 10:30 pm

    I’ve been studying ballistics in all these AR15 cartridges for several years. I currently shoot a custom AR10 in .260 that I drive a 139 grain Lapua scenar at 2800fps. This rifle is a tack driver but with the 24″ Lilja barrel and scope weighs almost 15lbs. Not exactly something you’d want to hump around all day long. I totally get why this 6mm ARC will take the shooting world by storm. This will give you basically 95% of a full power .243 Winchester in a relatively light and portable package. In the real world where shots at animals should rarely exceed 400 yards, this could easily become the next great American cartridge.
    I grew up with the ’06 and .270 as the premier western rifles, and as great as they are/were, there weren’t the bullets, optics, or rifles that could make humane shots consistently past 300 yards. These cartridges have been pretty much left behind, despite having the horsepower, because the vast majority are chambered in rifles that do not have a fast enough twist to stabilize the heavy for caliber bullets that are essential for long range
    This light, efficient, accurate, and balanced 6mm ARC will prove to be the goat for everything up to deer, and as a military round, could we’ll make the venerable.308 obsolete.

  • Terry June 5, 2020, 7:41 am

    I’ve been looking at a 6 DTI (6.8 SPC wildcat from Dtech) upper. As of 2020, are the Grendel issues of breaking bolts and spotty feeding completely solved? Those two things are what make me look at the 6.8 family longingly.

    Will this be a rock-solid reliable system overall? Will Odin guarantee reliable feeding?

    I’m definitely interested!

  • James Frame June 5, 2020, 6:33 am

    Exactly what I’ve been waiting for. I almost settled for the 6mm grendel, but was hoping for something with more support. I reload, so this should be fun.

  • Philip Palmer June 4, 2020, 11:46 am

    Not sure I see any advantage of this over the 6mmAR, 243LBC, or 6Grendel other than the availability of Hornady factory ammo from a single source (at the moment) which may or may not be accurate in another company’s barrels.

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