Grendel: Not quite the monster they think

6.5 Grendel in the Goldilocks position between 5.56 and 7.62.

In a long and thoughtful article on the 6.5 Grendel round J. Guthrie manages to interview Bill Alexander of Alexander Arms, cover the round’s genesis (including Alexander’s and others’ input) and its military potential, and talk a little about why it’s probably the best of all intermediate cartridges to date. And ultimately, he misses why the Grendel, as great as it is, is not a US issue round.

After almost two hours of discussing the long, tortured, and circuitous development and production history of the 6.5mm Grendel, I finally came right out and asked developer Bill Alexander if he thought the Grendel would ever get a shot at replacing the much-maligned 5.56x45mm NATO cartridge.

“Who knows?” Alexander asked rhetorically, knowing there is no clear-cut, defined path to adoption by regular U.S. military units. “It’s not about good weapons and ammunition any more, it’s a political game.”

After leaving the British defense industry and setting up shop at Radford Arsenal in Virginia, Alexander spent his time designing rifles and cartridges for Americans, not studying the procurement process.

If there were a clearly defined process, it could be upset at any point by meddlesome politicians, defense department bureaucrats, or the odd general. Despite the vagaries of the military’s equipment selection process, a quick analysis shows that the 6.5 Grendel is a legitimate contender to replace the entire M4/M16A2 family of rifles, including the SDM-R and SAM-R rifles, the M14-based family of enhanced battle/squad designated marksmen rifles, and the M110 sniper/squad designated marksman rifles. And it could be accomplished with two different uppers and loads.

via 6.5mm Grendel: The Round the Military Ought to Have – Shooting Times.

First, let’s just chalk the assertion that this round could replace both the CQB 5,56 shorty and the M110 semi-automatic sniper system and everything in between at once up to what it is: a writer’s hyperbole.

The 5.56mm round has strengths and weaknesses, both actual ones (which are well understood by combat users and decisionmakers) and mythical ones (which get most of the ink in the magazines and pixels on computer screens). It scores high on portability, reliability, and accuracy in the AR platform. Its most critical real weakness is terminal ballistics, where it’s hamstrung by several factors, including

  • Light bullets which shed speed and energy and suffer from displacement due to crosswinds.
  • Bullet design to a criterion that overweighted armor penetration at extreme range, yielding “icepick wounds” at combat ranges.
  • Increasing probability of hits at greater range thanks to improved weapons, ammo, sights and training, which paradoxically means more hits at the extreme range where energy is deficient
  • Case volume and neck size which conspire to require bullets with lousy ballistic coefficients.
  • Legalistically-required use of long-obsolete full-metal-jacket projectiles.

The Grendel is a clever attempt to address these issues in an AR platform. The stout case is perfect for longer, high-BC bullets that will still have supersonic velocity and substantial energy at ranges beyond 1000m. It can probably pass NATO’s silly 800-meter obsolete-Russian-helmet test with an ordinary lead-core FMJ bullet. It can be used in an AR, but needs a special bolt and magazine.

The heavier ammunition is a serious obstacle to adoption. At the higher levels, the military art that matters is the logistician’s. More weight and bulk means more cargo planes, ships, trucks, soldiers to haul the stuff. A hundred hands pass that round along before Joe Snuffy fires it at the enemy (or at the range… or 2LT Tentpeg ND’s it into a clearing barrel).  The reason the ordies chase the chimera of caseless ammunition is the potential 50% weight reduction and some secondary packaging advantages. The infantry soldier does not care how his ammo is packaged (assuming he can open the package, unlike the 24th at Isandhlwana — which turns out to be a historical myth), but the task force J-4 most assuredly does.

The Grendel also has another issue. It gets its best performance with the Lapua Scenar 123-grain bullet. Like every cartreidge out there, to unlock its full potential meticulous handloading is required, and the next best thing is meticulous manufacture. Nothing we’ve ever seen indicates that Lake City can produce at the quality metrics Hornady, for example, makes. That’s not a rip on LC — asking Steve Hornady to produce the quantity the Army ammo plant can generate would be equally unreasonable. But it’s fair to assume a half to one MOA degradation in mass produced ammo that must meet all US and NATO standards.

Here’s another version of the Grendel origin tale, by David Fortier.

The Grendel is one of several intermediate cartridges chambered in the AR these days. The military developed in-house a different round for a different purpose. The 6.8 SPC was developed by Special Forces specifically for CQB.  The design criteria were: increased terminal effect at very short ranges, and 100% compatibility with the M4 lower receiver and magazine. So this round began as a compromise from its initiation. In the end, it failed at working from the 5.56 magazine, and like the Grendel, needs a dedicated mag to feed reliably. Like the Grendel, capacity in a mag the length of the GI 30-rounder is 25 rounds.

Its development inside SF / SOF killed the 6.8 as far as Big Green is concerned. There were plenty of “reasons,” but they were excuses. The reason was this: NIH (Not Invented Here) at Army Ordnance, which has been made to eat too many breakfasts prepared by ARSOF or even other services’ or joint SOF lately.

And the 6.5 Grendel? Technically it would be a fine infantry combat round — for a service that did not already have a round that was good enough. There are a number of problems of a non-technical nature, but the primary one is that its degree of improvement over the 5.56mm is just not enough. Secondarily, its greatest improvement comes beyond  the most common infantry engagement range of  couple of hundred meters. (Yes, engagements in desert wars are longer-range; we’re talking about historical data and all wars in all terrain, because who knows where the next war is? For infantry, 800 meters is crew-served weapons range, not rifle range).

It is a standout cartridge, a great cartridge. Its superiority vis-a-vis 5.56 is very real in every factor except two that are retrograde (weight of ammo per round, and rounds per magazine), and it really stands out in terms of long-range accuracy and kill potential. But while that may be enough to make the difference for many personal AR buyers, it’s not a radical enough improvement for the ordnance establishment to even notice — not when that establishment has spent sixty years chasing the will-o-the-wisp that is the single shoulder weapon that fires bullets (or flechettes) and grenades (or shells).

Rifles dominate the thought of small arms people, especially collectors, target shooters, and hobbyists, but they don’t dominate the battlefield in terms of casualty production. Explosive and fragmentation weapons, like artillery and mortar shells and IEDs, have been the big killer at least since World War I. (The friend of ours with the highest Afghanistan body count by far — not that anybody’s counting, but he got lucky — used a 60mm mortar in direct lay against a large assault force whose assembly area was in his field of view — and fire).

The Grendel is up against an Army that’s already made a satisficing decision for the 5.56, and is not about to revisit it with an optimizing decision for the 6.5. Not when the guys whose job it is to pick the next weapon are chasing the technologies that are the weapons of the science-fiction future — and may always be.

Meanwhile, ironically, those SF soldiers whose predecessors developed the 6.8, have discovered the joys of room clearing with a short-barreled Mk17 SCAR. “Not optimum, perhaps, but it gets the job done.” — and there is no single sentence that better defines a satisficing option. This leaves all the alternative intermediate cartridges, including the potent 6.5 Grendel and the stout 6.8 PPC, as food for a thousand future “cartridge that should have been” magazine pieces.

If there are magazines in the future, other than the kind into which one loads cartridges.

4 thoughts on “Grendel: Not quite the monster they think

  1. McThag

    6.8 and 6.5 are vying to replace the .30-30 in the hearts of the American hunter, especially on hogs, now that the AR has replaced the lever-gun there.

    You’re right, they’re going to join 6mm SAW and .280 Brit for military application.

    Love the word, “satisficing” by the way.

    1. Hognose Post author

      I guess that depends on how close you are to the hogs. I’d think .300 Blackout would be pretty good hog medicine too. Nothing wrong with the .30-30 on whitetails in the East or on hogs anywhere, but times and styles change… slowly.

      “Satisficing” is one of my take-aways from B-school but apparently if I’d taken more econ as an undergrad I’d have seen it way back then.

      1. McThag

        Someday there’s going to be old coots who can’t be in the same room over the issue of 6.5 v 6.8 v .300 Blk like there’s coots who can’t talk about .270 v .280 v .30-06 when I was a kid.

        I wonder if .300 will survive when Rem stops pushing it (like so many other rounds they’ve championed). .300 Whisper and its clone have been a teeny niche for such a long time you have to wonder why it didn’t catch fire on its own; and something really great would have. 6.5 and 6.8 for example grew from word of mouth.

        1. Hognose Post author

          When I was a kid, it was the old-timers (hell…must have been in their 40s!) at the local airport flying Cubs and Champs, and arguing about whether the B-17 or the B-24 was the better plane… depending, of course, on which they had flown in Europe.

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