Hornady will introduce the 6mm AR in June 2020. This is a new SAAMI round that has been optimized for AR-platform guns*. The new 6mm AR is a 6.5 Grendel necked to 6mm with the shoulder moved forward around.030″. This pushed-back shoulder reduces case capacity (and velocity), however, we assume Hornady made this change to create a shorter proprietary chamber, so people couldn’t simply neck-down Lapua Grendel brass as they have done for years with Robert Whitley’s outstanding 6mm ARC wildcat. Click on the image for official SAAMI specifications:
Brownells has everything you need to get started with the 6mm AR. They have barrels, bolts and mags. You can even buy complete 6mm Rifles. Midsouth carries 6mm ARC ammunition and reloading tools. For general information, see 6mm ARC Wikipedia Info Page. What is the 6mm ARC Cartridge?
The 6mm ARC is a new SAAMI cartridge that uses a 6.5 Grendel casing necked down to 6mm bullets with the shoulder moved forward 0.030. It is designed to be used in AR15 platform rifles. You’ll also need a new bolt, mags, and barrel. If you already own an AR chambered for 6.5 Grendel you only need to replace the barrel. The bolt, magazines and gas system are all compatible with 6mm AR. Official SAAMI Cartridges (not wildcat).
Fits standard AR15 platform rifles
Fits Short/Miniature Action Bolt Rifles
> Efficient short, fat case design
More information on 6mm ARC can be found at the 6mm ARC Information Page. What do I need to shoot the 6mm ARC?
Faxon and Ballistic Advantage already produce barrels. More manufacturers are sure to follow. All other components for 6.5 Grendel rifles are already available. Aero Precision offers complete 6mm AR uppers. If you want to convert a standard AR15 upper that shoots 5.56×45 mm(.223 Rem) to 6mm ARC you will need a Type II 6.5 Grendel Bolt Carrier Group, a 6mm barrel and new magazines. Some people have said that standard AR magazines will work. But we’re sure you want magazines designed for 6.5 Grendel. Brownells has most of the equipment you need. Hornady has 18 videos of 6mm ARC. 6mm AR: Overview
6mm ARC: Handloading
6mm ARC Initial Offerings
6mm ARC: AR-15 vs AR-10
6mm ARC vs. 6.5 Grendel
6mm ARC vs Creedmoors
6mm ARC : 6.5 Creedmoor in the Gas Gun World
6mm ARC vs 308 WIN
6mm ARC – How it all began 6mm ARC – What is it?
Military Application of 6mm ARC
6mm ARC vs. 6.8 SPC
6mm ARC: Bolt Gun Application
6mm ARC: Cartridge Design
6mm ARC: Best AR-15 Cartridge
6mm ARC: Hunting
6mm ARC: Match
6mm: Barrel length * While 6-6.5 Grendel users are known for running high pressures, the 6mm ARC cartridge is rated at a moderate Maximum Average Pressure (MAP) of 52,000 psi by the official SAAMI specifications. It is best to keep semi-auto rifle pressures moderate for a number of reasons. Do not chase the speeds you would get with a bolt action gun.
