6mm ARC vs.

Given all the focus on the Army’s NGSW (Next Generation Squad Weapon) program when the Hornady 6mm ARC was introduced it was pretty easy to mix the two up. Typical social media and industry speculation fired up with a fury. Arguments amongst experts (real and self-delusional) spewed forth with ferocity. As the dust settled and reality set in this dissipated a bit. Thankfully most bantering moved back to more pressing issues like high demand (and low supply) of firearms or ammunition and that pesky election coming up in a few short months. Let’s now realistically compare the 6mm ARC vs. five of it’s perceived competitors.

My sources tell me the 6 ARC was a very small order for a specialized unit requested by an obscure R&D group that works under the DoD (Department of Defense) umbrella. That doesn’t mean others in that “community” or those in contact with them may not want 6mm ARC someday, or even give it a try sooner than later. For now, though, it is anything but a sea change amongst the broader Special Missions Units. That doesn’t take anything away from what the 6 ARC does and the companies who developed it. Our real questions are (A) What is the 6 ARC, (B) What does it do, and (C) is it doing something better than what you already own and love?


There will be no Math Test!

Years ago I authored an article titled “Lies, Damn Lies, and Ballistics”. It’s all about the lack of correlation between mapping out rounds on a computer and sending them downrange at targets measured in yards. If you are looking for reams of data or ringing steel the size of a car move on, I am NOT that guy, you will be very disappointed. What follows is my experience shooting the 6 ARC compared to five other calibers. Tests varied from 100-1100 meters (110-1200 yards, for the metrically challenged). Shots are on 12” round steel and 22” x 16” silhouette steel at 600 and 1100 meters. No math test required.

6mm ARC vs. the Rest – It’s Just an AR Cartridge

Unlike the NGSW the 6 ARC is a standard cartridge fired from an AR-15. Developed by Hornady in concert with Proof Research and Barret Rifles, the result is a SAAMI spec and full support. In simple terms, it’s essentially a “6mm Grendel” with the “Creedmoor” treatment, alterations to the shoulder and casing for better feeding, more consistency, and ease of mass production. If you have any doubt how well Hornady does this look no further than the 6.5 Creedmoor. Team Hornaday is the master, bar none. Already offering hunting, practice, and LE (TAP) rounds, the 6mm ARC starts with a firm leg up and should not be discounted without regard to why it was developed.

6mm ARC ammo

The rifles Barrett supplied for the DoD are top-notch, but they are just a modified REC-7 DI. I previously tested them in other calibers. They built these rifles with great attention to detail. The only difference is the Proof Research 18” 1-7.5 twist barrel, 6.5 Grendel bolt, and E-Lander magazines. I got hold of the barrel and some ammunition, the rest was already around and was mounted in a proven build, my Seekins Precision NX15.

This rifle originally started out as a 224 Valkyrie using their IRMT upper and NX15 lower. The IRMT upper locks the barrel in place with unparalleled rigidity. The handguard bolts to the upper eliminating impact shifts when setting the bi-pod or locking into a barricade or obstacle. Larue Tactical two-stage, small parts are Seekins, the stock is an LMT. The suppressor is an X2Devgroup, Orion X. It’s short at 6”, light at 16 ounces, and has no backpressure eliminating excess gas. Geissele fixed gas block was retained with no change in brass ejection pattern or bolt speed. All testing was completed using 108 grain ELDM from Hornady. Their 106 grain TAP round looks interesting with a .580 G1 BC but not available right now, will have to come back later on that.


6mm ARC vs. 5 Other Rifles and Calibers

Recoil is primarily a product of bullet weight. Velocity can be a factor, but given the same weight, recoil should be similar so I kept the weights as close as possible. It’s why the 308 is absent from this test. Factory match rounds start at 155 grains and go up. Excessive recoil, debilitating blast, and marked overpressure remain its claim to fame, thereby making it unsuitable for comparison for most of us.

6 ARC vs. other

Every rifle is a proven performer to 1100 meters and an AR using the same or similar suppressor, no brakes, flash hiders or conventional suppressors. They are an LMT Mars-H with a 20” 6.5 CM barrel, Leupold Optics Mark 5 HD 5-25 T3 reticle using 95 grain Hornady VMAX. ZevTech, 16” Proof Research .223 Wylde barrel, Leupold Optics Mark 6, 3-18 with a David Tubb DTR reticle and Black Hills 77 Grain TMK. LMT MWS, 20” 224V, Sig Sauer Tango 6, 3-18 MRAD Dev-L using Federal GMM 90 grain SMK and an 18” SS Match 6.8 SPC with 110 Grain VMAX. Modern Outfitters MC7, Proof Research 22” 6CM, Bushnell Elite Tactical XRS 4.5-30, Hornady 108 grain ELDM.


6 ARC Testing

To set up a viable 6mm ARC vs. these other calibers, I set 100-meter zeros, then confirmed at 1100 meters providing a proven hold at range. I also confirmed velocity for existing conditions. The 6 ARC proved at 2720 fps with a Density Altitude of 8800 feet. Each session started with a cold shot at 100 meters confirming zero while showing repeatability out of the bag. I followed up with three at 300 meters and a 600 Meter shot on a 22” x 16” silhouette steel.

Five more for effect as fast as I could get back on target ended the drill. No knobs, just a hold using the reticle, find it, read the wind, hold, and press, adjust as needed and repeat. Shots were aimed from a bi-pod, the rifle on the bench with me standing behind it. Long-range started with a cold shot at 600 meters using the reticle followed by one at 1100 meters using confirmed elevation dialed in, holding for wind. Five rounds for effect at 1100 ended the drill. Played at other stuff with the 6 ARC but that was the bulk of the testing.


6 ARC Results

100-300m:      Consistent 100 meter groups in the .60 -.75 inch range, 2.5-3.0 inches at 300 meters were the norm. Cold shots fell inside half an inch of the center a couple cut the red center dot. The 6 ARC was consistent, precise, and repeatable both on cold shots and groups but was about the middle of the pack with the rest. As the heaviest rifle tested recoil with the LMT Mars-H in 6.5CM was about the same as the Zev in .223 Wylde, the next best performer for groups. Clovered groups were the norm for both. This 6 ARC was an excellent performer, not a precision rifle but that’s not what it’s for. Given the need for a centered shot on a 6” roundish target from 100 to 300 meters, I would take it without hesitation.

6 ARC Cold Bore Shot

600m: Out of ten cold shots at 600 meters 7 hit home, pretty impressive. Hold for elevation never changed, 4 mils at the top garnered hits at from 4.2-4.7 mils each time, misses were generally wind. Five shot rapid-fire was not bad. The strings netted three or four out of five, misses were off the edge. It suffered no vertical stringing. I must note here how hard it hit. ZEV cleaned house using the David Tubb DTR reticle. Cleaned it all but twice missing one cold shot at this range. Did not hit as hard but it was no slouch, anything it hit would notice for sure. As for the 6ARC, I would take a vital shot at 600 meters without hesitation given a solid platform.

1100m: This is more academic than real, but they claim 6mm ARC performs at this range (compared to the .223 and 308). While it did well the clear winner was the 6CM, high BC and extra velocity are hard to overcome at this range. It still turns the steel and is very consistent holding 9 mils at the top. Did the 6 ARC outperform the .223? Absolutely, but not significantly better than the 224V with the 90 grain SMK. Both hit at around 12 mils, the 6ARC just hit harder. Consistency remained about the same with 2 or 3 out of five the norm. I never cleaned it with anything. It’s a long-distance for any of these and conditions were anything but ideal.

In between: Everything performed swimmingly between 100-400 meters as they should, once again the ZEV shines here with no recoil and consistent accuracy, almost boringly easy to get hits. Between 600-1100 was a different story, everything but the 6.8 SPC did well out to 800 meters including the 6 ARC hitting with a bit more authority than the rest. After that, it was the 6.5 and 6CM show. You could get hits at 900 meters with all of them, 5 shot strings were easiest with the Creedmoor’s and they ruled at 1100 meters.

6 ARC accuracy

My best target with 6mm ARC


Other Considerations

I had three “high capacity” magazines using white followers, two 17 rounders with green followers. Not a single stoppage amongst them too include a couple 17 round full auto mag dumps. Dropped on my M16 lower doubles and triples stayed on a full-sized silhouette out to 25 yards, stretched doubles to 50 yards.

6 ARC recoil

Recoil is subjective and using the same bullet weight they were all close. Probably the “most” recoil came out of the 6 Creedmoor. No surprise there since it is about the same weight as the 6 ARC and both used Proof Research barrels. LMT shot softer, exhibited a tank-like build, and proved great to shoot. However, I would not want to carry it far. The 224V and 6 ARC were identical to shoot and will probably stay my dedicated “1000 yard” rifle (s) both ringing steel pretty easily.

When it comes to the 6 ARC vs. everything else, it felt like carrying a 224V with the same length barrel. Clearly better to galivant around the countryside with then an AR10. Ammo capacity is about the same, 20 rounds with the longer Grendel mags. Unless you’re carrying this into combat, I’m not sure it matters. Most problems outside a war zone are handled nicely with 20 rounds and a couple of spare magazines. Given this or your typical AR10, no contest, the 6 ARC is much easier to carry.


Should I Switch to 6 ARC?

From an LE perspective, changing calibers is like pulling teeth on a ticked off Grizzley, very low rate of success and it’s hard to beat a .223 for patrol. Maybe in a rural area where ranges stretch out, but movement here will be a rarity. Outside a few very “special” special units, the military gets what’s issued. That won’t change and logistically the 6 ARC is still at baby steps. At the moment, it remains a proprietary caliber with one source of magazines and ammo, unproven. That will undoubtedly change, but not overnight. Those I know that can pick their own stuff are still proving out the 224V and many like it, not sure the differences are enough right now, time will tell.

Hunters may see an advantage as the ELDX and other hunting bullets are tested. When comparing 6mm ARC vs. 6.5 Grendel, you simply must ask, “Will it do something your 6.5 Grendel won’t?” Not that I can see. What about your 6.8 SPC? Maybe, if you are shooting farther out. My guess is that Hornady is banking on a broader market with hunters and enthusiasts, once more ammunition is available.

As much as I like shooting my 6 Creedmoor, every builder outside custom shops tells me it is a complete PITA to get to work on a large scale using factory ammunition, a real consideration. If this rifle is any indication all it took was a barrel, bolt, and magazine swap. Even with the cost of the Proof Research barrel it’ doable. Ran great with solid and repeatable accuracy using the same bullets as the 6CM. Slower, sure, but not enough to matter in the real world on real threats. You get “most” of the good without “most” of the bad and that is a pretty good start.

best 6 ARC rifle


Bottom Line

In the 6mm ARC vs. the rest of the calibers vying for your attention, we have to ask if it the next 6.5 Creedmoor. Probably not. You never know for sure, but it’s not a failure out of the box like so many others. Factory ammunition at normal prices (if that exists anymore) suitable for defense, duty, target, and hunting is more available than similar calibers after decades of use. Using already available magazines, bolts and the AR15 platform is a big plus. For those using 6.5 Grendel, it’s a 5-minute barrel change. Will it supplant mainstream calibers? I can’t see it, but for those who like to try something different it’s is a really nice option.

I started out a skeptic, not terribly excited about the 6mm ARC. With this testing behind me, I must say it was fun, I enjoyed it and will keep testing as new ammunition is available. Will it be my go-to bang away rifle, not likely. The Zev Technologies .223 is still the most fun you can have with an AR out to 600 meters. Hunting inside 300 meters the 300 HAMR rules that realm. Will it become my 1000 yards rifle, maybe, it is working against the 224V and the jury is still out and will be until I get my hands on their TAP round, I’ll keep you posted.

Editor’s Note: Looking for a deeper dive on the 6.5 Grendel vs. 6mm ARC? Read it here.

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