6mm AR
{{Short description|US centerfire wildcat rifle cartridge}}
{{distinguish|6mm ARC}}
{{Notability|Product|date=January 2023}}
{{infobox firearm cartridge
|name= 6mm AR
|image= {{CSS image crop
|Image = 6mm PPC.jpg
|bSize = 300
|cWidth = 110
|cHeight = 350
|oTop = 0
|oLeft = 100
|Location = center
}}
|caption=
|origin= United States
|type= Centerfire rifle
|service=
|used_by=
|wars=
|designer= Robert Whitley
|design_date=
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|is_SI_specs=
|parent=6.5 Grendel
|case_type=Rimless, bottleneck
|bullet=.243
|neck=.271
|shoulder=.4323
|base=.4433
|rim_dia=.4449
|rim_thick=.0591
|case_length=1.525
|length=2.260
|case_capacity=36
|rifling=1-8"
|primer=Small rifle
|max_pressure=
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|is_SI_ballistics=
|bwunit=
|bw1=105
|btype1=Berger VLD
|vel1=2750
|en1=1763
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|balsrc= http://www.6mmbr.com/gunweek068.html
}}
The 6mm AR / 6x38mm AR is an intermediate centerfire wildcat cartridge initially designed by Robert Whitley{{Cite web | url=http://www.6mmbr.com/gunweek068.html | title=6mmAR -- 6mm Solution for AR-15s (Grendel Brass) }} for long-range performance in an AR-15 rifle.
Description
The cartridge uses a 6.5 Grendel case that has been necked-down to accept a 6.2 mm (.243 in) bullet.{{Citation needed|date=September 2021}}
The 6mm AR takes advantage of the wide variety of 6.2 mm (.243 in) caliber bullets. Slim, long bullets with high ballistic coefficient are ideal for energy retention at long ranges.{{Cite web |url=http://6mmar.com/6mm_AR_Loading_Info.html |title=6mm AR Loading Info |access-date=2011-05-03 |archive-date=2011-04-22 |archive-url=https://web.archive.org/web/20110422003545/http://6mmar.com/6mm_AR_Loading_Info.html |url-status=dead }}
It is similar to the 6PDK which also uses a 6.2 mm bullet and a similar muzzle energy and case capacity to the 6mm AR and 6.5 Grendel, in a casing somewhat popular[http://ammoseek.com/most_popular_calibers.html?ar=1 ammoseek rankings] for the AR-15, a necked-down 6.8mm Remington SPC casing.{{Citation needed|date=September 2021}}
6mm AR Turbo 40 Improved
This variant uses an Ackley Improved fire formed case with less tapering and a 40-degree higher shoulder permitting a larger powder capacity. It is claimed by its maker to be capable of driving a {{cvt|100|gr|g|order=flip}} or heavier grain projectile at {{cvt|2900|ft/s|m/s|order=flip}} (satisfying the "6mm Optimum").{{Citation needed|date=September 2021}}
6mm Rat and FatRat
These wildcats also push forward the shoulder of the same necked Grendel case similar to the Turbo 40, yielding more powder capacity. {{cvt|100|gr|g|order=flip}} or heavier grain VLD boat-tail bullets have to be seated deeply within the case neck, however, rendering some of these volume gains illusory but there is an increase in volume even with the longer bullets nonetheless.{{Citation needed|date=September 2021}}
6mm Grinch
Similar to the 6mm Turbo 40 and 6mm FatRat, the 6mm Grinch has a blown-forward shoulder on par with the 6mm Dasher to eke maximum powder capacity from the necked Grendel case.{{Citation needed|date=January 2023}}
See also
References
{{reflist}}
{{Intermediate cartridges}}
{{7.62×39derivatives}}
Category:Pistol and rifle cartridges
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