6mm ARC: Difference between revisions

| name = 6 mm6mm Advanced Rifle Cartridge

| production_date = 2020-present2020–present

| parent = [[.220 Russian]]/6.5mm Grendel<ref>[https://www. name="firearmsnews.com"/editorial/new-from-hornady-6mm-arc/376909 Hornady 6mm ARC Cartridge - What You Need to Know]</ref>

| bullet_ref = <ref name="6mm-ARC-drawings">[{{Cite web |url=https://saami.org/wp-content/uploads/2020/06/6mm-ARC-Public-Introduction-Rev-2020-06-18.pdf |title=Public Introduction - 6.5 Creedmoor - 6mm-ARC-Public-Introduction-Rev-2020-06-18.pdf] |access-date=2020-07-24 |archive-date=2020-10-01 |archive-url=https://web.archive.org/web/20201001120735/https://saami.org/wp-content/uploads/2020/06/6mm-ARC-Public-Introduction-Rev-2020-06-18.pdf |url-status=dead }}</ref>

| rim_dia = 1011.44mm* (0.4410 in)20

| rifling = 190.5 mm (1:7.50" in)

The '''6 mm6mm Advanced Rifle Cartridge''' (6×38mm), or '''6mm ARC''' for short, is a [[6mm caliber|6mm6 mm (.243) caliber]] [[intermediate cartridge|intermediate]] [[rifle cartridge]] introduced by [[Hornady]] in 2020, as a low-[[recoil]], high-[[accuracy]] [[long range shooting|long-range]] [[cartridge (firearms)|cartridge]], designed for use in the [[AR-15]] platform at request of a specialized group within the U.S. DoD for its multipurpose combat rifle program.<ref name="Hornady-6mm-ARC-info-page" />

== Performance ==

The cartridge makes use of 6&nbsp;mm (.243 in) [[bullet]]s, which are known for their high [[ballistic coefficient]]s due to the high [[sectional density]] with less [[drag (physics)|drag]] and better [[kinetic energy|energy]] retention at extended ranges. With the release in 2020, Hornady also launched three factory loads with {{cvt|103|,|105|and|108|gr|g}} bullet weights and advertised G1 ballistic coefficients of .512, .530 and .536 respectively.<ref>[https://www.all4shooters.com/en/shooting/ammunition/hornady-6-mm-arc-new-ar-15-caliber-features/ Brand new rifle caliber: 6 mm ARC, Hornady's Advanced Rifle Cartridge! | all4shooters]</ref>

The 6mm ARC is a medium-power cartridge comparable to the [[6.5mm Grendel]], but with better ballistics thanks to the greater muzzle velocity achieved by using lighter 6mm6&nbsp;mm bullets and enough power to make use of the heavy 6mm6&nbsp;mm bullets. Some have stated that it offers comparable ballistics to larger 6mm6&nbsp;mm cartridges like the 6mm Creedmoor and [[.243 Winchester]], but out of a smaller cartridge, however this simply is not true when comparing muzzle velocities between them.<ref>{{cite web|url=https://www.loaddevelopment.com/6mm-creedmoor-hunt-and-competition/|title=6mm ARC vs 6mm Creedmoor|website=loaddevelopment.com}}</ref> What the 6mm ARC does offer though, is almost comparable velocities and ballistic performance, but out of a compact cartridge that has lowerless feltperceived recoil and fits ininto the standard [[AR-15]] length actions.

In addition to the above comments, there is some confusion with regards toregarding the 6 &nbsp;mm ARC’sARC's performance. This is because loading data given in some manuals, such as the ''11th Edition Hornady Reloading Manual'',<ref>[https://www.hornady.com/reloading/handbook Hornady 11th Edition Reloading Manual]</ref> for example, has two sets of data. The first set of data is loaded to the SAAMI MAPmaximum (Maximumaverage Averagepressure Pressure(MAP) of 52,000 PSIpsi, which is stated to be suitable for gas-operated firearms, such as the AR-15 platform and its derivatives. The second set of data is loaded to a MAP of 62,000 PSIpsi, which is stated to be for use with bolt action guns, such as the [[CZ 527]]. The Hornady manual states that this second set of data should not be used in gas-guns. Due to the lower MAP, the performance of 6 mm6mm ARC ammunition loaded to gas-gun pressures will, on average, be less than firearms loaded to bolt action pressures when using the same barrel length. When using shorter barrels, which are common on gas-guns, the difference will be even more pronounced.

For example, the data in the Hornady 11th Edition Manual for an 18" in (457 &nbsp;mm)-barrelled AR-15 platform firearm was on average 200-300 200–300&nbsp;ft/s (60-90 60–90&nbsp;m/s) less than the data for the 24" in (610 &nbsp;mm)-barrelled CZ 527 bolt action rifle.

For an ordinary AR-15 rifle chambered for the [[.223 Remington|.223 Rem]]/[[5.56mm NATO]], a new [[gun barrel|barrel]], [[magazine (firearms)|magazine]] and [[bolt (firearms)|bolt]] are required to convert to the 6mm ARC.<ref>[https://www.gunsamerica.com/digest/hornadys-new-6mm-arc-odin-works-barrels-first-field-tests/ Hornady's NEW 6mm ARC & Odin Work's Barrels - www.gunsamerica.com]</ref> The 6mm ARC utilizes the same bolt head size as the [[6.5mm Grendel]], and 6.5mm Grendel-compatible [[STANAG magazine|AR-pattern]] [[box magazine]]s have also been used successfully with the 6mm ARC.<ref>[https://gununiversity.com/6mm-arc-review/ gununiversity.com | 6mm ARC Released / Hands-On Testing and Comparisons, by Ryan Cleckner 3 June 2020]</ref> The 6mm ARC therefore can also be a suitable chambering for shorter "mini-action" [[bolt-action rifle]]s.{{CnCitation needed|date=September 2021}}

== See also ==

* [[6 PPC]] https://en.m.wikipedia.org/wiki/6mm_PPC