The AR-15 is the most common rifle sold in the United States over the past few years, and it is easy to understand why. The simple, basic, iron-sighted rifle hasn’t changed a great deal since it hit the civilian market 49 years ago in 1964, but in the past decade in particular, modern manufacturers have taken the modular nature of Eugene Stoner’s rifle and run wild with the possibilities.
One of the possibilities of the AR-15’s modular design is the ability to change just the barrel (and sometimes the bolt) and to fire cartridges far different than the common 5.56 NATO and .223 Remington calibers that made the firearm famous. AR-15 shooters know they have the option of picking cartridges ranging from the cheap and ubiquitous .22LR to the tiny-but-fast pistol-class 5.7x28mm, and up through the rifle calibers to the heavy-hitting short-range power of the .50 Beowulf — capable of taking down buffalo, bear, and other dangerous game.
One of these new cartridges designed specifically for the AR-15 is the 6.5 Grendel, which is one answer to the problem of extending Stoner’s mid-range rifle into a true-long range platform.
Named after the mythical monster from the Anglo-Saxon epic Beowulf, the 6.5 Grendel was introduced to the world by Bill Alexander of Alexander Arms in 2003 at the long-distance precision-rifle training ranges of Blackwater (now Academi) in Moyock, North Carolina. The wind-slicing 6.5 bullet out-shot the standard 7.62 NATO cartridge used by many of America’s law enforcement and military snipers at long distances, with roughly half the recoil of the 7.62 round. It more than doubled the range of the standard 5.56 NATO cartridge and carried far more down-range energy at any distance.
The cartridge itself is designed to take advantage of the long, narrow profile and energy efficiency (called the ballistic coefficient) of the 6.5mm class of bullet, which has long been popular in Europe but had never really caught on in the United States thanks to the established preference of American shooters for .30-caliber rifles. A key development took place when competition shooter Arne Brennan took the nearly dormant 6.5 PPC cartridge developed in the mid-1980s in 1998, and spent two years testing thousands of rounds.
By 2002, Bill Alexander, who was then working for the British Ministry of Defense, heard about the 6.5 PPC cartridge and discovered it would would fit the .50 Beowulf bolt he’d already developed. After some collaborative work between Brennan and Alexander, Alexander took their work to Janne Pohjoispaa to finally devlop specs of what became the 6.5 Grendel cartridge, tweaking to work off an existing .220 Russian case under manufacture by Lapua.
Why is the 6.5 “special”?
At “normal” limits of the AR-15’s range with .223/5.56 ammo between 300-500 yards, the cartridge’s power is anemic, and hits on reactive steel targets must be heard rather than seen. At these same short- to middle-distance ranges, the 120-123 grain 6.5mm bullets of the Grendel hit reactive targets with far more authority than the typical 55-62 grain bullets commonly used in .223 Remington/5.56 NATO-chambered AR-15s.
A decade after it’s unveiling, the 6.5 is still the premier long-range AR-15 rifle cartridge, and Bill Alexander’s company still makes some of the most accurate examples of the rifle.
I’ve had the opportunity to fire an Alexander Arms rifle belonging to a competition shooter in the company’s head-of-the-class GDMR configuration, and found it to be soft-recoiling and laser accurate. At 500 yards with a good scope, a good shooter will find that ringing 8″ steel plates from the prone position is monotonously repetitive. A .223 bullet at these ranges won’t move a steel plate of any size, and is useless in ethical hunting terms for anything much larger than a prairie dog. The Grendel is just starting to strut its stuff at the same range, making the AR-15 a legitimate beanfield rifle for whitetail deer, or a mountain rifle for elk or bighorn sheep.
While the 6.5 Grendel excels at distance as it was designed to do, it is also arguably the best “all-around” AR-15 cartridge, with a few caveats:
- It has more range than the .223/5.56, the 6.8 SPC, the .300 AAC Blackout, or any other known factory loading that can be chambered in an AR-15.
- It has more down-range energy past 700 yards than any other known factory loading chambered in an AR-15.
- It has more muzzle energy at short-to-medium ranges than the standard .223/5.56 loading, and is roughly comparable to the 6.8 and 300 AAC Blackout in terms of ballistic performance at this ranges.
The downsides of the 6.5 Grendel are few, but noteworthy:
- Ammunition is more expensive and difficult to find than that of the .223/5.56.
- It requires a different bolt, barrel, and magazine than a standard AR-15, and the magazine capacity is generally limited to 26 rounds instead of the normal 30.
- The .6.5 Grendel bolt does not last as long as the bolt of an AR-15, and some claim the barrel may wear slightly faster, depending on the ammunition used and barrel twist rate.
While I don’t have much practical use for the full 24″ barrel of the Alexander Arms GDMR as a shooter with longer ranges would, I’ve found that a shorter-barreled Alexander Arms rifle or the 18″ cut-rifled, progressive-twist barrel of my Templar Custom MCWS to be a solid compromise of the 6.5 Grendel and AR-15’s best properties. It gives me a sub-minute-of-angle (MOA) accurate rifle deadly for hunting out the 450-yard limits of wooded rolling hills in the Carolina Piedmont, but still doubles as a more than capable range and self-defense rifle.
You can find specific AR-15-compatible cartridges that might fill specific niches better that the 6.5 Grendel, but few do it all as well.
More on guns from Bob Owens at PJ Lifestyle: