I prefer a 6.5mm, in a beefed-up AR-15 platform. To that end, I last week sent the following letter-appeal to Freedom Group, Inc. Chairman & C.E.O., George Kollitides:
"Dear Mr. Chairman:
I applaud the Remington Design Team for giving our sport shooting world the R-15 .30 Remington AR: a rifle with a robust AR-10 breech, in a lighter, shorter AR-15 platform. The concept is a long time coming. And, I dare state its arrival is welcomed by many.
So, at a time when rifles and ammunition 'are flying off the shelves,' why does a quick check of two major gun distributors, Budsgunshop.com and Grabagun.com, reveal that the Remington R-15, .30 RAR, is In stock, while other R-15 Models are Out of stock? And, a check of popular ammunition distributor, Midwayusa.com, shows that of the four products listed under .30 Remington AR, two are In stock, while many other calibers are Out of stock. I submit that the otherwise desirable R-15 .30 RAR platform is shackled by a cartridge, which downrange performance fails to impress, and which single-stack, low-capacity magazine and odd-sized case rim diameter both leave much to be desired.
In view of the above, let's consider a 21st Century-designed cartridge, with impressive downrange performance, that double-stacks in an AR-15 magazine and which case rim diameter, midway between the 5.56x45 and .30 Remington AR, is shared by other cartridges. Already impressive, in the standard AR-15 platform, its performance really shines in bolt-action rifles: the 6.5mm Grendel. Typical wait times for 6.5mm Grendel Barreled Upper Receivers are measured in months. And, a check with Midwayusa.com ammunition reveals that of the seven 6.5mm Grendel products, all, are Out of stock.
Let's compare the retained velocity, energy values of the .30 Remington AR, 150-grain Core-Lokt Pointed Soft Point (BC - 0.314), Muzzle Velocity - 2575 fps (24" test barrel), with the 6.5mm Grendel, 139-grain Lapua Scenar (BC - 0.615), Muzzle Velocity - 2305 fps (16" barrel AR-15) and 2700 fps (22" barrel bolt-action rifle), at 300, 400 and 500 yards:
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 yards . . . . . . . . . . . 400 yards . . . . . . . . . . 500 yards
24" R-15, .30 Remington AR: . . . 1804 fps/1084 ft-lb . . . 1588 fps/840 ft-lb . . . 1397 fps/650 ft-lb;
16" AR-15, 6.5mm Grendel . . . . . 1922 fps/1140 ft-lb . . . 1804 fps/1005 ft-lb . . . 1692 fps/884 ft-lb;
22" Bolt, 6.5 mm Grendel . . . . . . 2277fps/1600 ft-lb . . . 2147 fps/1423 ft-lb . . . 2020 fps/1259 ft-lb.
In short: the 6.5mm Grendel is a prime candidate chambering for the R-15 .30 RAR platform. Unencumbered by the penalties its increased bolt thrust on the smaller AR-15 Bolt impose, it can fly with the super-size AR-10 Bolt --- and, a 2.300" magazine, please!
Thank you for your consideration.
In retrospect, had Remington initally offered a 6.5/.30 RAR or a 6.5/450 Bushmaster in addition to/instead of the .30 Remington AR, that would have really stirred up the sport shooting world!