"ARC stands for Advanced Rifle Cartridge, and this is a new cartridge from Hornady for the AR-15 platform, so that kind of defines it out of the gate", said Jayden Quinlan, Hornady ballistician. "Most people are familiar with the length requirements of an AR-15 magazine, so that's kind of the starting design envelope."
Over the last several years, Hornady ballisticians have taken lessons learned from the company's experience with the 6.5 Creedmoor, the 6.5 PRC and the 300 PRC and combined it with the latest advancements in cartridge design, bullet construction and powder formulation. Combined with these elements was a desire to create a new AR-15-length round that had more punch and more reach than .22-cal. bullets could offer.
Hornady also examined the popular world of long-range shooting and discovered that, while shooters used everything from .224-cal. bullets to 6.5mm bullets, the majority of shooters were finding success with 6mm cartridges, because it offered a balance of great ballistics, wind deflection, low recoil, reach and impact on target.
"What the 6 ARC is is a well-rounded optimization of an AR-15 cartridge that will do everything very well," Quinlan said. "You can shoot long-range with it, you can hunt with it, recreational shooting, the barrel life is very good, the recoil is low, it's a lightweight AR-15 platform. You're getting performance from that system that, traditionally, you'd have to go to an AR-10 platform to get."
Conversations on what would eventually become the 6mm ARC didn't start from a match-shooting standpoint, though. In fact, the question that spurred development of this new round came from the military development side of Hornady. The problem faced by the U.S. Military is how to maintain the size and weight benefits of the AR-15/M-16 platform while enhancing the reach and punch of today's Soldier.
Traditionally, the standard-issue 5.56 NATO round has an effective range that maxes out between 500-600 meters. For targets beyond this range, the Military deploys 7.62 NATO platforms that are heavier and lower-capacity than 5.56 NATO rifles and light machine guns.
"The goal was, 'Can we design something that has all the weight and size benefits of the AR-15 but have the external ballistic and terminal performance benefits that you would traditionally have with the 7.62 NATO?" Quinlan said.
From a military standpoint, Hornady's 6mm ARC is designed as an improvement over both the 5.56 NATO and the 7.62 NATO rounds traditionally employed in the U.S. arsenal. Conceivably, this means that the new round from Hornady could be used as a potential replacement for both NATO rounds in the future.
In recent years, the U.S. Military has expressed interest in a new, general-purpose round as outlined in its NGSW program, but to date, entrants and program requirements have centered upon a 6.8mm design.
Compared to 5.56 NATO, the 6mm ARC offers substantially less drop and wind deflection and provides the ability to shoot much more accurately at longer distances. The Hornady 6mm ARC is capable out to and beyond 1,000 yards, and recoil between the two cartridges is similar. According to Hornady reports, magazine capacity is also comparable between the two.
Compared to 7.62 NATO/.308 Win., the Hornady 6mm ARC features similar ballistic profiles and beats the .308 Win. in terms of wind deflection. The trajectory of both the 7.62 NATO and 6mm ARC are said to be similar. However, the main material benefits between 7.62 NATO and 6mm ARC platforms come in the weight reduction, recoil reduction and magazine capacity of both.
Rifles chambered in 6mm ARC are, on average, 30 percent lighter than comparable 7.62 NATO rifles, and there's a 30 percent reduction in the ammunition weight alone. The reduced recoil of 6mm ARC rifles means that shooters can spot their own shots, preventing the need for a spotter along with a shooter in a combat environment. Higher magazine capacity on 6mm ARC rifles also means that users can spend more time shooting and less time reloading.
The Hornady 6mm ARC cartridge case uses a 6.5 Grendel bolt, which are commonly available, and shooters of the 6.5 Grendel will find common elements between the two cartridges while also recognizing that the 6mm ARC offers some benefits in addition to the Grendel design.
Upon launch, Hornady will offer several factory loadings for the 6mm ARC, including a Hornady Black option designed for optimum performance in gas-operated rifles and loaded with a 105-gr. BTHP bullet. This load features a muzzle velocity of 2,750 FPS recorded out of a 24" barrel. The other option available at launch is found in the Hornady Match lineup, which uses the 108-gr. ELD Match bullet. Hornady plans to make a Precision Hunter load available in fall 2020 loaded with a 103-gr. ELD-X bullet.
A number of rifle manufacturers will also offer rifles chambered in 6mm ARC. For more information on those manufacturers and more details on the new cartridge, visit hornady.com.