Comparing All The 6.5mm Cartridges (That Actually Matter)
Travis Olander 01.01.24
In the last decade, endless 6.5mm cartridges have entered the market. We’re not talking some random wildcat hand loads. These have, by the numbers, become mainstream cartridges – but there are simply too many. Plenty of them might just be fads riding the .264″ bandwagon. With so many rounds crowding the space, it can get confusing picking out what’s actually useful, and what roles each round fulfills best (if any, at all). Let’s look at the best 6.5mm cartridges.
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6.5 Creedmoor (The “New .308 Winchester”) – 6.5mm Cartridges
- Case Length: 1.920″
- Overall Length: 2.825″
- Case Capacity: 52.5 gr H2O
- Muzzle Velocity (120 gr): 3,020 FPS
- Muzzle Energy (120 gr): 2,430 ft. lbs.
Of all the 6.5mm loads, Creedmoor’s probably the one you recognize. It might be the only 6.5mm cartridge you recognize, and for good reason: It’s become arguably the most popular 6.5mm cartridge to come out in recent years, and it effectively functions as a contender for replacing the aging but still loved .308 Winchester. Because of its performance and compatibility with .30-caliber receivers, it’s now one of the more popular rounds found in so many .308-type AR uppers and build.
Although practically identical in length (.308 measures about 2.8″ in total length, too). At a glance, Creedmoor and .308 Win appear evenly matched: if both casings fire a 12o- to 125-grain load, .308 produces around 3,100 FPS – about 80 more than Creedmoor. But Creedmoor retains more energy downrange, with a notably higher ballistic coefficient, less drop per hundred yards and greater wind resistance. Although they’re evenly matched up to around 600 to 800 yards, depending on the comparative loads, 6.5 Creedmoor begins showing its superiority at a kilometer – it’ll drop up to 1.5 feet less at this distance. In spite of its higher BC and range, 6.5 Creedmoor’s felt recoil is practically identical to .308 Winchester. Better performance in exchange for the same shoulder punch is always a plus. In some cases, Creedmoor’s actually a fair bit softer on the shoulder sinew, offering up to 5 pounds less felt recoil.
6.5 PRC (The 6.5mm Laser Pointer) – 6.5mm Cartridges
- Case Length: 2.030″
- Overall Length: 2.955″
- Case Capacity: 62 gr H2O
- Muzzle Velocity (147 gr): 2,960 FPS
- Muzzle Energy (147 gr): 2,782 ft. lbs.
6.5 PRC exists to fulfill one purpose: To provide the greatest accuracy and performance of any .264″ load that isn’t strapped to a massive casing requiring a long action. With an overall length about 0.13″ longer than 6.5 Creedmoor, 6.5 PRC will fit handily in most short actions, while providing supersonic velocity at up to 1,650 yards. To be blunt, that is insane for any short action cartridge. For comparison, .50 BMG remains supersonic at about 1,500 yards.
6.5 PRC also manages to provide bullet drop similar to long action cartridges that require way more wrangling. It’ll manage to drop just 6″ at 300 yards, 18″ at 400 yards, and 36″ at 500 yards. That’s similar to .30-06 and .300WM without the massive actions, longer barrels, and heavy felt recoil. But for all its speed and laser trajectory, 6.5 PRC suffers modest barrel life – about 1,300 rounds before you need to re-barrel. But, given 6.5 PRC is often loaded in the world’s most expensive PRS and F-class rifles, the cost of some new rifled round bar probably isn’t a material concern for those taking full advantage of its capabilities.
6.5 Grendel (Made for The AR-15) – 6.5mm Cartridges
- Case Length: 1.520″
- Overall Length: 2.260″
- Case Capacity: 35 gr H2O
- Muzzle Velocity (120 gr): 2,700 FPS
- Muzzle Energy (120 gr): 1,942 ft. lbs.
6.5 Grendel is to 5.56 and .223 what Creedmoor is to .308 Winchester: A suitable replacement for an aging and comparatively inferior round, accomplishing better performance in the same receiver and platform, save for swapping the barrel and bore itself. The only difference, here, is that Grendel is actually bigger overall, ditching the .22-caliber bullet for, well, obviously the 6.5mm at .264″ in diameter. Coupled with a 22% greater capacity – 5.56 NATO offers 28.5 gr. H2O – you’re getting more power and still obtaining velocities similar to 5.56’s heavier (62- or 63-grain) loads.
The power difference is stark at greater differences, too. While 5.56 NATO is practically effective at 300 to 400 yards, 6.5 Grendel maintains supersonic flight at 700 yards, significantly improving its trajectory and ballistic coefficient at distances well beyond what the typical AR-15 could ever hope to achieve. But none of this is surprising given Grendel’s, on average, double the weight, with a much higher sectional density that improves wind resistance, too. The only drawback is the extra recoil – but Grendel still punches softer than Creedmoor, making it ideal for converting .22-caliber receivers.
6.5x55mm Swedish (The Original 6.5) – 6.5mm Cartridges
- Case Length: 2.165″
- Overall Length: 3.150″
- Case Capacity: 57.9 gr H2O
- Muzzle Velocity (120 gr): 2,810 FPS
- Muzzle Energy (120 gr): 2,108 ft. lbs.
Produced in 1891, the original 6.5mm cartridge remains popular today. Although the 6.5 craze seems to have begun in earnest only a few years ago, it was actually extensive testing conducted by the Swedish-Norwegian Rifle Commission over a century before that concluded 6.5mm bullets are, in fact, superior to most similar calibers (like 8mm, 7.5mm, 7mm, and 6mm). Originally chambered in military Mausers, 6.5×55 Swedish found its way into the hands of fullbore biathlon athletes – those crazy skiers who shoot rifles on the slopes – before being retired in favor of .22 LR in 1975. But 6.5×55 remains a popular cartridge for target shooting and hunting large game in North America and Europe.
American gun makers Barrett, Remington, and Ruger all make actions for the Swede, while Blaser, CZ, Steyer, Mauser, Tikka, and Howa make actions globally. Although 6.5×55 fits in long actions, the tradeoff is that it can technically provide better performance than even 6.5 PRC. The Swede makes a fine hunting cartridge, too, with affordable rifles: The Tikka T3x costs about $1,000, and most over Swede rifles come in at around this price point; some can be had for $800 or less.
6.5-284 Norma (The Bench Round to Beat) – 6.5mm Cartridges
- Case Length: 2.170″
- Overall Length: 3.228″
- Case Capacity: 68.33 gr H2O
- Muzzle Velocity (120 gr): 3,000 FPS
- Muzzle Energy (120 gr): 2,497 ft. lbs.
6.5-284 Norma is, as of this writing, arguably the most accurate 6.5mm cartridge available. Used by professional marksman Rich DeSimone to set a 1,000-yard world record shot group, which measured just 1.564″ in diameter, translating into about 0.15 MOA of accuracy. For most cartridges and rifles, this level of sub-MOA performance is unheard of at distances even just a fraction of a kilometer. Little more needs to be said, here.
This level of performance has, naturally, spawned a healthy niche market for rifles chambered in the stuff. Christensen Arms makes over a dozen variants of its Norma long action, specifically tailored for bench rest shooting. Savage also makes its dedicated 12 Series F-Class Rifle for the Norma, complete with custom, triple pillar bedding, a beautiful heavy-duty laminate stock, and an extra heavy 30″ barrel – all for just $1700; not bad for this level of performance.
6.5-300 Weatherby Magnum (The Fastest 6.5mm) – 6.5mm Cartridges
- Case Length: 2.825″
- Overall Length: 3.600″
- Case Capacity: 98 gr H2O
- Muzzle Velocity (130 gr): 3,476 FPS
- Muzzle Energy (130 gr): 3,487 ft. lbs.
If the Norma can set a record, it stands to reason the 6.5-300 Weatherby Magnum, capable of obtaining about 3,900 FPS at the muzzle with 100-grain loads, should be more than capable of beating it, right? Although no one has attempted to, there’s little reason to doubt this insanely proportioned 6.5mm variant.
With the most case capacity, the 6.5-300 Weatherby Magnum is also the fastest commercially available 6.5mm load current available. This is perhaps the most specialized – and temperamental – cartridge on this list, too. Barrel life is typically expected to average fewer than 1,000 rounds, and soft tipped bullets are likely to mushroom and scatter, providing poor terminal performance in hunting applications.
But with the right .264″ bullets, the 300 Weatherby iteration of the 6.5 is unbeatable for range, potential accuracy, and knockdown power. Zeroed at 300 yards, you’ll experience just 7″ of drop at 400 yards, with drop at shorter distances approaching basically nothing. In short, if you want a 6.5mm that literally shoots like a laser at typical game-taking distances – with a guarantee it’ll instantly drop any big game in North America – the 6.5-300 Weatherby is a top choice. Now that you’re learned up on all the 6.5 fads, see why 6.5 Grendel is one of the best deer cartridges.
