Sporting Systems
Oregon's Indoor Shooting Range
Bi-Mart
J&B Firearm Sales
Bear Creek Arsenal
Southwest Firearms Forum
HighLine Firearms
JavaScript is disabled
Our website requires JavaScript to function properly. For a better experience, please enable JavaScript in your browser settings before proceeding.

  • Join the #1 community for gun owners of the Northwest

    We believe the 2nd Amendment is best defended through grass-roots organization, education, and advocacy centered around individual gun owners. It is our mission to encourage, organize, and support these efforts throughout Oregon, Washington, Idaho, Montana, and Wyoming.

    Free Membership Benefits

    • Fewer banner ads
    • Buy, sell, and trade in our classified section
    • Discuss firearms and all aspects of firearm ownership
    • Join others in organizing against anti-gun legislation
    • Find nearby gun shops, ranges, training, and other resources
    • Discover free outdoor shooting areas
    • Stay up to date on firearm-related events
    • Share photos and video with other members
    • ...and much more!

6mm arc

The 6 mm Advanced Rifle Cartridge (6×38mm), or 6mm ARC for short, is a 6mm (.243) caliber full-power rifle cartridge introduced by Hornady in 2020, as a low-recoil, high-accuracy long-range cartridge designed for the AR-15 platform.
The cartridge makes use of 6 mm (.243) bullets, which are known for their high ballistic coefficients due to the high sectional density with less drag and better energy retention at extended ranges. With the release in 2020, Hornady also launched three factory loads with 103, 105 and 108 gr (6.7, 6.8 and 7.0 g) bullet weights and advertised G1 ballistic coefficients of .512, .530 and .536 respectively.

View More On Wikipedia.org
Recent contents
  1. helix6sk

    Hornady Once-Fired 6mm ARC Brass (200 each bag)

      1. For Sale
    • $100
    • Redmond
    • Oregon
    Once fired Hornady 6ARC brass. Bags of 200, can split into smaller quantities. Total 800 at the moment, but will have more soon. Some is stainless tumbled, some is not. Will ship at cost. Could fill a flat rate box and price accordingly as well. 50 cents each OBO. Will discount for larger...
  2. Demonian

    6MM ARC AR build

      1. For Sale
    • $1000
    • Amity
    • Oregon
    Selling my 6MM ARC Aero lower and slick side upper. Ballistic Advantage 16" Fluted Barrel Faxon Adjustable Gas Block. Brownells light weight bolt carrier. Grendel Hunter bolt. Raptor lite charging handle. Stinger 15" MLOK handguard. Magpul dust cover. Magpul bipod. some generic muzzle brake i...
  3. Wdaniel

    6mm arc barrel comparison, Proof Research or Helix 6?

    Looking for some real world feedback on 6mm arc carbon fiber barrels in AR platforms from both companies. I have a Lantac 6arc with a Proof stainless barrel and after having some feed issues, I’ve switched out the buffer system and it’s shooting great. Sub MOA with factory ammo. Looking to...
  4. daviddex5832

    Radian Model 1, 6mm ARC, Proof Research, JP Rifles

      1. For Sale
      2. For Trade
    • $2000
    • Tualatin
    • Oregon
    Parting ways with my Radian Model 1 in 6mm ARC, built this from a builders kit and threw in some of the best parts I could get my hands on. Has maybe 200-300 rounds on it, runs very well so far. Feel free to ask any questions about the build, I absolutely love this rifle but life happens...
  5. arrowshooter

    More This v That : 6.5mm Grendel V 6mm ARC

    Starting July 2026 barrels will have to go through an FFL for a background check here in California, so I am coming up with things that I may be interested in building in the future and covering barrels for modern sporting rifles now. First up I thought that another 6xx would be fun, but have...
  6. M

    6MM ARC brass once fired

      1. Want to Buy
    • PORTLAND
    • Oregon
    Looking for some 6MM ARC brass once fired. Looking for 100+ to 1000 of them prefer Hornady or Starline. Thanks for your time.
  7. Fieryotaku

    6mm ARC 12" upper.

      1. For Sale
    • $900
    • North Plains
    • Oregon
    Rainier Match 12" barrel. RIS 2 MK18 rail. Aero M4E1 upper. Cmc enhanced bcg. Lantac 6mm arc bolt. Radian raptor charging handle. Sico ASR brake. Scope peq and bipod not included. 900. Maybe 200 rounds down the pipe.
  8. R

    24" AR-15 in 6mm ARC Precision Long-Range Setup

      1. For Sale
    • $650
    • Riddle
    • Oregon
    This is a sub-MOA semi-automatic AR-15 chambered in 6mm ARC, built for precision shooting. It's a true tack driver with Hornady 108gr ELD Match ammo, consistently producing sub-MOA groups. With 105gr handloads, I've achieved ½-inch groups at 100 yards. Note: This rifle does not perform well with...
  9. G

    6mm ARC complete upper package

      1. For Sale
    • $600
    • Ridgefield
    • Washington
    6mm ARC complete upper package Includes: (1) Bearcreek Arsenal 20” SS barrel , right side charging complete upper. Shot (40) times Hornady 108 grain ELD factory ammo. Barrel seasoned per LaRue Tactical process. This is a good shooting upper but needs a better shooter than me to ring out its...
  10. K

    Odin upper 6mm ARC

      1. For Sale
    • $850
    • Summer
    • Washington
    Complete Odin upper (88rd through) 18” stainless steel barrel 2 mags 40+ rounds Hornady ELD X 103 grain
  11. cityrice

    6mm ARC 18" upper

      1. For Sale
    • $550
    • Hillsboro or Saint Helens
    • Oregon
    I have a complete upper for sale, shoots great and likes CFE223. 6mm ARC Upper BCM Thermal Fit Upper Ballistic Advantage 18" barrel Superlative Arms adjustable gasblock Radian Raptor Charging Handle Free Float MLOK with ARCA Plate Only selling because I'm reloading other calibers. $550 OBO DM...
  12. B

    BA 6mm Arc 20" barrel

      1. For Sale
    • $100
    • Spokane
    • Washington
    $100 shipped - BA 6arc 20" DMR profile barrel with about 200 rounds down the pipe. Shot around 1.5" with most stuff, with precision hunter 103gr eldx usually showing sub moa. Didnt play with reloads too much, but a 103 gr eldx and lower charges of LeverRevolution seemed to show promise!
  13. MDDM

    6mm ARC

      1. Want to Buy
    • Hillsboro
    • Oregon
    Looking for at least a couple hundred rounds of factory 6arc for baseline testing of a new build. Let me know what you've got
  14. B

    Aero 6mm ARC upper

      1. For Sale
    • $275
    • RENTON
    • Washington
    $275 Decided to stick to 6.5 grendel since I have less time to reload than I thought and 6.5 factory ammo is a bit friendlier on the wallet. Shot about 200 rounds through this upper, about 50/50 reloads and factory ammo. Shot solid, I'd say averaging around 1-1.5" with hornady precision hunter...
  15. D

    6mm arc upper complete

      1. For Sale
    • $625
    • Dallas
    • Oregon
    Aero upper Ballistic advantage 16” premier barrel Aero adjustable gas block grendal hunter bcg Ballistic advantage handguard Aero breach charging handle(little coating damage) Deadair keymo brake Also have a spare Odinwerks 22” arc barrel
  16. orchemo

    Ruger American 2 in 6mm ARC

      1. For Sale
    • $525
    • Portland
    • Oregon
    Ruger American Rifle Gen 2 Ranch version with 16 inch barrel 6mm ARC Shoots great Comes with 2 magazines About 150 rounds fired includes everything from the box and the box !! Scope and rings pictured are NOT included
  17. ChrisWolf

    Proof Research, .223 Wyld 6mm ARC 6.5 Grendel 5.56 Barrel.

      1. For Sale
      2. For Trade
    • Hillsboro
    • Oregon
    FSOT 18” Proof Research barrel .223 Wylde. Used $500.00 16” Proof Research barrel 6mm ARC Lightly Used $700.00 18” Draco 6.5 Grendel Lightly used $525.00 with 7.62 bolt(for small frame AR Carriers) 16” LANTAC RAVEN Rifle length gas Unused $200.00 I will sell the entire DRACO upper 1250.00 Specs...
  18. M

    Aero precision 6.5 bcg

      1. For Sale
    • $150
    • Lakewood
    • Washington
    Brand new never fired 6.5 Grendel/6mm arc bolt carrier group bought to build 6 arc and haven’t got around to it and moved on to something else
  19. Roadpirate2322

    6mm ARC Noveske bbl 18unfired.

      1. For Sale
    • $950
    • Albany
    • Oregon
    18" Noveske barrel and headspace's JP bolt. Centurion upper with a little paint on it. New radian SD charging handle. Geissele 16" mk16 blemula fde ASR 3 prong flash hider 7- 25 round mags 2-5round mags. $950 ftf in Albany. $975 shipped
  20. Roadpirate2322

    7x 6mm arc 26rnd duramags

      1. For Sale
    • $110
    • Albany
    • Oregon
    7 Brand new duramag 26 rnd 6.5 Grendel/6mmARC magazines. $110 ftf Albany $120 shipped.
Sporting Systems
Bi-Mart
Collectors West Gun Shows
Bear Creek Arsenal
Cerberus Training Group
Brownells
Oregon's Indoor Shooting Range
Southwest Firearms Forum
Optics Planet
Midway USA
Back Top