Long-Barrel, Bolt-Action 6.5 Grendel Handloads
Date: Oct 18 2021
The 6.5 Grendel was one of a host of cartridges manufactured to increase terminal performance from the AR-15. That goal has been addressed in the past by expanding the neck of the original .223 Remington/5.56 NATO case, like the .25x47 Sharps, .300 AAC Blackout or .350 Legend, as examples, or creating fat-bodied cartridges held within the 2.26 inch confines of the AR-15 magazine, but enlarging the bolt head, like the .224 Valkyrie, .22 Nosler, 6mm ARC or 6.8 Remington SPC, as examples. The 6.5 Grendel, is one of the latter. Of all of the incarnations of such AR-15 inspired cartridges, it could easily be argued the Grendel provides a superior combination of energy delivery, flattened trajectory and minimized wind drift at average 100- to 300-yard hunting ranges with the 6mm ARC providing better ballistics only when ranges stretch beyond 400 yards.
The 6.5 Grendel was the brainchild of Bill Alexander, owner of Alexander Arms and former British Ministry of Defense contractor. Alexander was seeking a more powerful AR-15 cartridge to hunt white-tailed deer. Competition shooter Arne Brennan and Lapua Engineer Janne Pohjoispaa aided in the effort. Unveiled in 2003, the Grendel blew the doors off the .223/5.56mm, and even bettered .308 Winchester/7.62mm NATO ballistics at longer ranges due to superior ballistic coefficients and despite producing half the recoil of the NATO round. The Grendel, shooting 123-grain bullets, remains supersonic past 1,200 yards. The Grendel also commonly produces low extreme velocity spreads in the neighborhood of 10-25 feet per second (fps). Based on the .220 Russian/6mm PPC case, overall loaded length (OAL) is 2.26 inches, head diameter .439 inch and the 30-degree shoulder was moved forward to increase powder capacity. Grendel brass hold small rifle primers and neck/shoulder areas are thickened to improve reliability in semiauto actions.
The Grendel efficiently handles light varmint bullets weighing from 85 to 95 grains at around 2,900 fps, and heavier bullets up to 130 grains at around 2,500 fps, suitable for big game like deer and hogs due to near-standard 1:8-inch rifling twist.
Upon introduction, the Grendel was a trademark cartridge, limiting rifles and ammunition to Alexander Arms wares. Hornady Manufacturing Company obtained licensing in 2010 to produce ammunition, brass and dies, with the trademark released in 2011 and the round approved by The Sporting Arms and Ammunition Manufactuers’ Institute (SAAMI) in 2012.
To this point, all of my extensive 6.5 Grendel experience has included an Alexander Arms AWS AR-15. The vast majority of that shooting was conducted at night, using thermal imaging optics while culling invasive Texas hogs. I’ve also shot a substantial number of hogs with a .223 Remington AR-15 and 75- to 90-grain bullets (20-inch barrel), the new 6mm ARC with 103-grain bullets, .300 Blackout from an Alexander Highlander Pistol (10.5-inch barrel) and a 6.8 SPC (18-inch barrel). All got the job done. All pale in comparison to the 6.5 Grendel while shooting 123-grain Hornady SST or 129/130-grain Hornady SST/Swift Scirocco II at average hog-hunting ranges (75-100 yards) with the ARC again, gaining an edge at ranges exceeding 400 yards. Heavier bullets can be safely loaded, but represent a point of diminishing returns due to powder intrusion dictated by magazine limitations.
My AR experiences sparked curiosity about the possibility of more recently released bolt-action Grendel rifles, and especially CZ-USA’s long-barreled Model 527 based on “Mini-Mauser” actions. While modern AR-15s are certainly robust enough to handle maximum loads, to a point, most include shorter barrels for easier handling. The Grendel gains about 20-25 fps for each inch of barrel added. A well-made bolt rifle, like CZ’s Model 527 Varmint MTR (25.6-inch, 5/8x24 threaded barrel, .886-inch muzzle diameter, 1:8 twist) might also allow slightly heavier loads without affecting rifle longevity.
The CZ Model 527 Varmint MTR test rifle included controlled-round feed, claw extractor, adjustable trigger and hammer forged barrel. The 16mm scope mounts are integrated into a forged, square bridge receiver, with proprietary CZ-USA rings required (available from CZ, Talley or Warne). The 527’s all steel, five-shot detachable magazine allows a slightly longer OAL of about 2.335 inches (though slightly longer rounds, loaded with sharp-pointed bullets will chamber freely). The rifle includes a highly-ergonomic Turkish walnut stock with vertical grip, large palm swell, tasteful stippling and wide forearm that sits steadily on a bag or rifle cradle. It includes a 14-inch length of pull. The two-position safety includes a push-forward for safe, pull-back, to fire configuration backwards to American shooters. Engaging the safety locks the bolt. The Czech-made rifle weighs 8.7 pounds out of the box, adding a Czech-made Meopta Optika6 MeoPro 4.5-27x 50mm scope set in CZ rings brought the final weight to 11.99 pounds. The adjustable trigger broke at about 4.5 pounds out of the box and does not include the set feature of other 527 models.
Components used to assemble all loads included new Starline brass, Winchester Small Rifle Primers, Redding Series B full-length dies and an Area 419 ZERO Reloading Press. Powders were pretty straight forward and likely on hand if you handload for any classic varmint cartridge – though some of the more common formulas didn’t make the cut, as I was determined to include newer options. Bullets were chosen to demonstrate the Grendel’s versatility, from true varmint bullets to hard-hitting, big-game and long-range hunting numbers.
Speer’s 90-grain TNT was chosen to serve for serious varmint shooting. With a G1 ballistic coefficient of .281, this bullet provided superior BCs compared to standard weight .224-caliber bullets, giving shooters a decided edge when facing windy conditions. To that end, Ramshot X-Terminator, Alliant Reloder 10X and Hodgdon Benchmark provided maximum velocities, with no loads grouping more than an inch. Ramshot X-Terminator, 30 and 31 grains, provided the tightest groups with this bullet, .21 and .39 inch at 2,715 and 2,753 fps, respectively. Alliant Reloder 10X did best with a maximum load of 28 grains, producing a .45-inch group. Hodgdon Benchmark started a bit shaky, 28.5 grains producing a .93-inch group, but 29.5 and 30.5 grains improved groups instantly, producing .59- and .56-inch groups at 2,751 and 2,874 fps.
Nosler’s 100-grain Partition (G1 BC .326) is the original “controlled-expansion” bullet, and when shot from the Grendel, provides a dead-on, reliable big-game payload that is ideal for short to medium range deer or hogs. Vihtavuori N133, Hodgdon CFE-223 and Alliant Power Pro Varmint were paired with this bullet, producing an uninspiring 1.43-inch group average. The best group was .72 inch at 3,112 fps using a compressed 33-grain load of Alliant Power Pro Varmint. All other loads grouped from 1.12 to 1.84 inches – not overly impressive but certainly all the accuracy needed for deer- and hog-sized game at any reasonable range.
Hornady’s 120-grain ELD Match, with its excellent .486 G1 BC, offers a long-range edge, whether shooting targets or wild boars. ELD Match bullets will expand on game, though my experiences are limited to average-sized hogs and large varmints. This bullet was paired with Ramshot TAC, Accurate A-2460 and Alliant Power Pro 2000 MR. An immediate accuracy improvement resulted after moving on to this bullet, just one load breaking outside an inch while using Ramshot TAC, a powder that also turned in the least impressive overall groups with this bullet. Accurate A-2460 turned things around with 25 grains assembling a .28-inch group at 2,371 fps, 26 grains .43-inch at 2,485 and 27 grains .62-inch at 2,514 fps. All loads using Power Pro 2000 MR averaged in the low to high .60s at similar velocities.
The 123-grain SST from Hornady remains, to my mind, the best all-round 6.5 Grendel big-game bullet. I’ve taken more hogs with this single bullet from the Grendel than I can accurately recount. Tracking is rarely required following vital shot placement, the Super Shock Tip dumping maximum energy on target, the InterLock crimp assuring bullets remain largely intact following bone hits. Most hogs, even 300- to 350-pound boars in full flight, roll on impact. Accurate A-2520, IMR-8208 XBR and Hodgdon Varget provided the fuel for this bullet. All A-2520 loads grouped at less than an inch, while Varget disappointed with groups measuring 1.08 to 1.57 inches – certainly tight enough for big-game work. However, the 1.08-inch group including 2,455 fps velocities. IMR-8208 XBR provided the best accuracy, but somewhat lackluster velocity. The maximum load hit 2,394 fps, the most accurate (.45-inch) 2,288 fps. For close-range hunting purposes, I’d go with the hot Varget load to gain a touch more knockdown energy.
Berger’s 130-grain VLD Hunting is a bullet I wagered would function better in the bolt rifle than an AR-15. This was driven home after loading, it’s 2.33-inch OAL still required single feeding in the bolt, but provided impressive accuracy. IMR-4166 Enduron, Shooters World Match Rifle and Alliant Reloder 15 are all temperature-stable formulas (IMR-4166 and CFE-223 also including copper-erasing ingredients) offered excellent velocities. Match Rifle and Reloder 15 provided top velocities (2,469 and 2,443 fps with maximum loads). IMR-4166 did best with a maximum load of 26 grains at 2,204 fps (.56-inch), Match Rifle printing .59 and .51 inch at 2,342 and 2,469 fps using 29.5 and 30.5 grains of powder (the latter a compressed load), Reloder 15 turned in a .67-inch group at 2,358 fps with a lightly-compressed load of 28 grains.