Introduced in 2009 for Remington's R-15 MSR (AR type rifle), the .30 Rem. AR uses modern powders in a short, fat case to achieve performance with bullets weighing 150 grains or less between that of the .30 Remington rimless and the .300 Savage. To wit, it launches a 150 grain Core-Lokt PSP bullet at a claimed muzzle velocity of 2575 fps from a 24" test barrel. Able to launch a 125 grain Core-Lokt PSP bullet at 2800 fps, it easily outperforms the 7.62x39mm Soviet AK-47 cartridge.

From its name, the .30 Remington AR sounds like it should be related to the old .30 Remington, but it is not. However, despite their completely different shape and dimensions, the two cases do have about the same powder capacity (approx. 44 grains in the .30 AR).

The .30 Rem. AR is loaded to a much higher Maximum Average Pressure (MAP) of 55,000 psi. The .30 Remington, introduced in 1906 for the Model 8 autoloading rifle, is loaded to a MAP of about 38,000 CUP. Autoloading rifles have changed in the last 100 years!

The .30 Rem. AR is a rimless, bottleneck cartridge based on a modified .450 Bushmaster case necked-down to accept .308" diameter bullets. The rim diameter is .492" and the head diameter is .50", making this a rebated rim case. The case measures .488" right behind the shoulder, which is formed at 25 degrees, and the neck length is just a hair under one caliber at .305". The maximum case length is 1.530" and the maximum cartridge overall length is 2.260". The .30 AR uses small rifle primers.

I understand that to make the .30 AR work, Remington had to adapt an AR-10 bolt to the R-15 receiver. This seems like a lot of trouble, but the end result is worth it.

The .30 Remington AR is one of the best MSR hunting cartridges for Class 2 game to come down the pike. The 150 grain factory load delivers 1395 ft. lbs. of energy on target at 200 yards, easily outperforming the .300 Blackout, 6.8mm SPC, 7.62x39 and even the .450 Bushmaster. Among AR-15 cartridges available from the major US ammo manufacturers, only the 6.5mm Grendel comes close in 200 yard energy (1390 ft. lbs with a 123 grain Hornady SST bullet), but the .30 AR is throwing a bigger, heavier bullet.

Here are the Remington factory ballistics for the 150 grain Core-Lokt load (velocity in feet per second / energy in foot-pounds):

• Muzzle - 2575 fps / 2208 ft. lbs.
• 100 yards - 2302 fps / 1675 ft. lbs.
• 200 yards - 2047 fps / 1395 ft. lbs.

Here is the published trajectory of that load:

-1.5" at muzzle; +2.5" at 100 yards; +2.2" at 150 yards; 0 at 200 yards; -4.3" at 250 yards

According to the Hornady Handbook, reloaders can duplicate the factory ballistics with Hodgdon H322 or LEVERevolution powders. Using H322 and a 150 grain Hornady bullet, the starting load is 30.5 grains for a MV of 2200 fps. The maximum load is 36.5 grains of H322 for a MV of 2600 fps from a Remington R-15 rifle with a 22" barrel. These loads used Remington brass and WSR primers.

As you can see, the .30 AR makes a decent 250 yard deer cartridge, which is certainly more than can be said for the .303 caliber 7.62x39 Soviet. The .30AR has not achieved as much success in the marketplace as expected and Remington dropped it from the R-15 line in about 2015, which I find strange. I am not a fan of autoloading hunting rifles in general and ARs in particular, but if I were, the cartridge I'd want in my MSR is the .30 Remington AR.