SMALL ROUND, LONG-RANGE, AND SHROUDED IN MYSTERY

I'm a big fan of new things and long-range shooting. While 6mm ARC isn't as new as it was two years ago, it's still really new on the overall timeline of cartridges. Time will tell if this new 6mm round has the legs to stand on its own. For now, the DOJ is helping prop it up.

What is it good for? Where did it come from? Can you even find any ammo? We'll dig into all of this and more.

ORIGIN OF THE 6MM ARC

6mm ARC hit the market mostly by surprise in 2020. Hornady had been working on it for a while, but the company was very hush-hush over the cartridge. And with good reason – it was developed for immediate adoption by “a notable Department of Defense entity.” 

What does that mean? In the immortal words of Top Gun's Maverick, “That’s classified.”

All we really know is the 6mm ARC is currently in the hands of expert marksmen using it in far-off lands to put down threats. More than that, we can only guess.

While the Army, Navy, and Marines won’t be adopting it en masse anytime soon (or ever), the reason for its existence is pretty cool and makes a lot of sense.

There was a need, by some unknown unit in the military, for a cartridge that could perform at over 600 yards while firing from a standard M4 package and didn’t weigh the shooter down as .308 Winchester rifles and ammo do.

Before the nay-sayers start in with their tired lines of how you should just work out more and carry the weight, keep in mind that special forces operators are some of the most physically capable people on the planet. More weight is bad, always. A lot of time and money goes into making gear weigh less.

6.5 Grendel was reportedly considered but rejected due to reduced lethality at 400-plus yards. Ultimately, Hornady looked at both .22 and 6mm as the answer to its woes. While .22 caliber bullets have served well in the past, 6mm bullets are better at long range and proved to be better able to retain lethality past 600 yards.

A lot of testing, refining, and math later, and we have the 6mm ARC.

BALLISTICS

Something you don’t find very often, but 6mm ARC has two sets of ballistics. While designed for gas rifles, like the AR-15, 6mm ARC has quickly been adopted by shooters as a bolt-action cartridge also.

Other 6mm cartridges are super popular with long-range bolt rifle shooters, such as 6 GT, 6 BRA, 6 XC, 6 BR, and 6 Creedmoor. 6mm ARC is another in that same vain of low-recoil 6mm cartridges that perform amazingly well at long range.

For gas guns, factory loads and hand-loading data caps out at about 54,000 PSI – mostly because that is what is safe for an AR-15 bolt face sized for 6mm ARC. Bolt-action 6mm ARC rifles can handle more spicy pressures of about 62,000 PSI.

Right now, Hornady is the only brand offering factory-loaded ammo for 6mm ARC, and it only offers ammo safe for AR-15s, but it does have hand-loading data available for higher-pressures exclusively designed for bolt-action 6mm ARC rifles.

6mm ARC Ballistics — 105gr ELD-M 18″ Gas Rifle

6mm ARC Ballistics — 105gr ELD-M 24″ Bolt-Action Rifle

PRACTICAL APPLICATIONS

Designed for special forces doing special missions, that doesn’t mean all this is good for is shooting bad guys. 

Long-Range Target Shooting

For the same reasons that this is a great caliber for special forces, it’s a great caliber for long-range target shooting. Lightweight ammo, rifles that are easy to handle, low-recoil, and outstanding ballistics make this a solid long-range round.

While not as popular in PRS as 6 GT, 6 BRA, 6 Dasher, and some of the other slightly larger 6mm calibers, the 6 ARC does reasonably well.

Even if you’re not looking to take the crown at PRS events, 6mm ARC is just a lot of fun. Easy to shoot, accurate, and low-recoil makes for a downright fun cartridge. 

Hunting

Not ideal for big pieces of meat, the 6 ARC still does incredibly well against hogs, smaller deer, and just about any predator that requires culling. If you hand load you can make some outstanding varmint rounds using published load data. The 58gr V-MAX moving at ~3,600 FPS will put down a lot of prairie dogs at some long ranges.

AMMO AND AVAILABILITY

Factory ammo is only made by Hornady, for now. While this is a SAMMI spec ammo that other brands can load at will, none have so far. Sadly, 6mm ARC hit the market right as the ammo panic of 2020 was getting really, really, bad. While manufacturers are still recovering from that event, it’s unlikely we’ll see anyone new offering 6mm ARC anytime soon.

Brass is also almost impossible to find since Horandy is putting all of its new brass into loaded ammo manufacturing. You can convert 6.5 Grendel brass into 6mm ARC brass, but results have been inconsistent for most people.

Reloading dies are available from RCBS and Hornady.

Loaded 6mm ARC ammo is available online from a range of stores, but the price starts at over $1.50 per round before shipping.

Bottom line, the biggest downside of 6mm ARC is actually getting your hands on some. Hornady is committed to making ammo, and I think we’ll see other brands come online sooner or later, but for now, this is what it is.

LOOSE ROUNDS

I’m a big fan of 6mm ARC. It is low-recoil, easy to use, fun to shoot, and does really well at long range. We’ll have some more 6mm ARC content coming soon so come back to take a look at that!

Until then, good luck finding enough to keep your rifles fed. If you can, I would strongly recommend getting into reloading.

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