| .30 RAR (.30 Remington AR) | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Size comparison with .223 | ||||||||||||
| Type | Rifle, Centerfire | |||||||||||
| Place of origin | United States | |||||||||||
| Production history | ||||||||||||
| Designed | 2008 | |||||||||||
| Manufacturer | Remington | |||||||||||
| Produced | 2008–present | |||||||||||
| Specifications | ||||||||||||
| Parent case | .284 Winchester | |||||||||||
| Case type | Rimless, bottleneck | |||||||||||
| Base diameter | .500 in (12.7 mm) | |||||||||||
| Rim diameter | .492 in (12.5 mm) | |||||||||||
| Rim thickness | .054 in (1.4 mm) | |||||||||||
| Case length | 1.53 in (39 mm) | |||||||||||
| Overall length | 2.26 in (57 mm) | |||||||||||
| Case capacity | 44 gr H2O (2.9 cm3) | |||||||||||
| Rifling twist | 1:10 | |||||||||||
| Primer type | Large rifle | |||||||||||
| Maximum pressure | 55,000 psi (380 MPa) | |||||||||||
| Ballistic performance | ||||||||||||
| ||||||||||||
| Test barrel length: 24 Source(s): http://accurateshooter.wordpress.com/2008/10/15/remington-introduces-new-30-remington-ar-cartridge/ | ||||||||||||
The .30 Remington AR / 7x39mm Remington AR is an intermediate cartridge created in 2008 by Remington Arms to fill a perceived gap in performance on large game between the .223 Remington and larger cartridges such as the .308 Winchester. [1] The design of the cartridge is considered a joint effort between companies under the "Freedom Group" name through a private equity firm [1] and included such companies as Bushmaster, DPMS and Remington itself. It is a rebated rim cartridge designed to fit Remington's R-15 semiautomatic hunting rifle. It was made to fit the dimensional constraints of the AR-15 magazine and is based on a modification of the .450 Bushmaster, which in turn is based on the .284 Winchester. [2]
Remington was the only company that manufactured this ammunition and its components. [3] The cartridge was a commercial failure and has been discontinued by Remington.[ citation needed ]
Starting with a .450 Bushmaster case, Remington trimmed the length to 1.525 in from the original 1.7 and necked it down to accept a conical .308 in diameter bullet with a 25-degree shoulder. [4]
The rim size is .492 in and because the round generates 55,000 psi, Remington opted to use a .308 rifle bolt in a 5.56-sized rifle for increased case support. [4] The rim was widened from the .473 in of the parent case to prevent the use of a weaker .450 Bushmaster bolt with this cartridge. With a 150 grain bullet, the round travels at 2,575 feet per second (fps). [5]
Performance tests between the .30 RAR and the .308 Winchester show that while the .30 RAR does have a good muzzle velocity, the energy it is capable of delivering on target at around 400 yards decreases significantly. [6] Combined with the poorer ballistic coefficients of the lighter projectiles (.267 for the 125-grain Core-Lokt), this makes the .30 RAR a cartridge suited to ranges around 300 to 400 yards, although this can be extended with projectiles of higher ballistic coefficient (.341 for the Speer TNT 125 grain).[ citation needed ]
A side effect of the short, wide case is that the Remington R-15 rifle, which was designed alongside the cartridge, uses a four-round, single-stack magazine. [1]