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.
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.
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.)
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.
6MM ARC PERFORMANCE
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 ODIN Works to learn more