April 14, 2022
By Steve Gash
Until recently, metric cartridges were not particularly popular in the United States. Most of the earlier ones were military rounds from foreign nations. Over here, we like to think in fractions; everybody knows what a quarter of an inch is, but throw in some metric numbers and brows furrow. Saying “6.5mm” just doesn’t sound as “American" as .264 inch.
But the worm has turned on the 6.5mm cartridges, and that’s for the better. The list of excellent modern 6.5mm rounds is long, but the 6.5 Creedmoor and the 6.5 PRC lead the pack.
The 6.5 Creedmoor was developed by Dennis DeMille and Dave Emary of Hornady in 2007 and was approved by the Sporting Arms and Ammunition Institute (S.A.A.M.I.) in 2008. Fairly recently, it has become a monster hit, and it is easily the most popular round of its caliber in existence, at least in the U.S. It has an excellent record in the hunting fields on big game as well as on target ranges because of several interacting virtues. It has really kicked the development of 6.5mms into high gear.
The other reason for the 6.5mm’s revitalization is the new 6.5 PRC. PRC stands for “Precision Rifle Cartridge,” and precise it is. The PRC is a collaboration of George Gardner of GA Precision and Hornady, and it finally came to life in 2013. Its success is not at all surprising as it faithfully incorporates the design criteria of the Creedmoor for chamber, case, and bullet. A senior gun company engineer has told me that as long as everything is lined up straight at the get-go, good accuracy will result.
The bullet diameter of 0.264 inch and the traditional fast twist used for these two rounds allow the use of long-for-caliber bullets of suitable weight for big-game hunting and long-range target shooting. In addition, both the 6.5 Creedmoor and the 6.5 PRC can be housed in short-action rifles that are light and handy in the game fields.
The reasons for the cartridges’ phenomenal successes are numerous, but they hinge on careful design and execution of the rounds’ chambers, throats, leades, and cartridge cases, as noted above. In the design of the 6.5 Creedmoor, the placement of the case shoulder, neck length, bullet-seating depth, and chamber throat design are all geared toward that perfection. These features improve the length-to-diameter ratio for better ignition and powder burn, the sharp 30-degree shoulder helps the powder burn inside the cartridge case so that less powder is burned in the barrel throat and down the bore. This also makes the cartridge more efficient, so it takes a little less powder to achieve a given velocity, and bullets are seated out a bit longer so that more room inside the cartridge case is left for propellant.
Riflemakers scrupulously follow S.A.A.M.I. specs for chamber, bore, and cartridge design, and ammo companies make sure that the bullets they load in these cartridges mate harmoniously with the chamber and throat. Thus, virtually all 6.5 PRC and 6.5 Creedmoor and rifles, even inexpensive ones, shoot great.
The 6.5 Creedmoor was originally designed for the National matches, and in that role, it has excelled, but it also turned out to be a terrific hunting round. Plus, factory ammo is so accurate that handloaders are hard-pressed to duplicate it. However, Hornady prints the load data for its highly accurate factory loads on the boxes, so reloaders can duplicate the load at home. The 6.5 Creedmoor shoots long, skinny bullets with high ballistic coefficients for flat trajectories, and their high sectional densities and sufficient weights ensure deep penetration. This makes it a highly effective hunting cartridge.
I scoured the Internet and ammo catalogs and found 66 factory loads for the 6.5 Creedmoor and 14 for the PRC. I may have missed some loads, but what I found gives you an idea of the popularity of both rounds.
And this popularity has spawned a wealth of specialized factory loads that can cover virtually any shooting situation. Representative summaries of factory loads for each cartridge are shown in accompanying charts. While the available weights of 6.5mm bullets range from 90 to 156 grains, and their ballistic coefficients and sectional densities are eye-popping, probably the most popular bullet weights fall into two categories: those for big-game hunting and those for long-range target shooting.
Bullet weights of the factory loads ranged from the Hornady 95-grain V-Max to the Berger 156-grain EOL (Extreme Outer Limits) Elite Hunter, with numerous specific designs for game of various sizes, from varmints to mule deer and maybe even elk. Bullets for various types of target shooting, including the fast-growing sport of long-range PRS are available.
The light recoil and modest muzzle blast of the Creedmoor make it a great choice for new shooters, as well as seasoned riflemen. My Creedmoor is an early Ruger Hawkeye with a 26-inch barrel, and it has used been on axis deer and Texas hogs, and it performed perfectly on all critters.
The 6.5 Creedmoor and the 6.5 PRC cases look a lot alike, except the PRC is considerably fatter. The Creedmoor case is the .30 TC case (developed by Hornady in conjunction with Thompson/Center) necked down to 6.5mm with the same 30-degree shoulder. Its length is 1.920 inches, and the base diameter is 0.473 inch. If this dimension sounds familiar, it is because it’s the same as the .30-06 and the multitude of other cartridges based on the .30-06.
The 6.5 PRC case is based on the .300 Ruger Compact Magnum case (another Ruger-Hornady collaboration) shortened by 0.070 inch with a 30-degree shoulder angle. The PRC’s base diameter is 0.532 inch, which is the same as the many belted magnum cases extant. However, the PRC case tapers from 0.532 inch to 0.516 inch, while the taper of a belted magnum begins at 0.512 inch ahead of the belt. The PRC’s case is 2.030 inches long, and this gives the PRC considerable volume for its short length.
Some Comparative Numbers
Let’s look at some comparative numbers. The 6.5 Creedmoor (CM) has a capacity of about 47 grains of water, while the PRC’s volume is 64 grains. That’s an increase of about 36 percent. Maximum powder charges in the PRC are about 30 percent greater than those for the CM, and this advantage produces a significant increase in bullet velocity.
It is no surprise that the same long-for-caliber bullets with sky-high ballistic coefficients and sectional densities that excel in the CM work splendidly in the PRS with the 1:8-inch twist rates standard in rifles for both rounds. Everything I said in favor of the CM applies in spades to the PRC; it’s like the CM on steroids.
Looking at some of the ballistic differences between the two rounds, we find that the CM might seem a bit overpowered for varmints, but there’s no denying that critters at any reasonable range would be in serious trouble from a hunter armed with the 6.5 PRC. The Hornady 95-grain V-Max loaded by Hornady and Federal exits the muzzle at 3,300 fps and 2,900 fps respectively. And any of the long-range target loads would quickly relocate a marmot to chuck heaven.
Such lightweight bullets are not currently loaded in the PRC, which is primarily stoked with big-game bullets of modern construction weighing 120 grains to 143-grain bullets at very impressive velocities. As I said earlier, I found 14 factory loads listed for the 6.5 PRC, and the hunting loads’ factory-rated velocities range from 2,900 fps to 3,100 fps depending on the bullet weight, and that’s a significant advantage for these bullet weights over the CM.
Comparing some of the new high-tech bullets that are factory-loaded in both cartridges (the data are summarized in a separate chart), the listed velocity of the 6.5 CM Hornady 143-grain ELD-X is 2,700 fps. In the 6.5 PRC, its speed is 2,950 fps (250 fps and 9.2 percent increase). Muzzle energy goes from 2,315 ft-lbs to 2,745 ft-lbs, a 19.4 percent increase. This makes for a flatter trajectory with the PRC. For example, with a 200-yard zero, the CM drops 43.85 inches at 500 yards, whereas with the PRC, it’s 35.98 inches. At 1,000 yards, these drop figures are 300.58 inches vs. 245.81 inches respectively.
For other examples, the velocities of the Nosler 140-grain AccuBond and the 142-grain AccuBond Long Range are 250 and 300 fps faster in the PRC and produce increases in muzzle energies of 20 and 24 percent respectively. The importance of these differences depends on the goals of the shooter, but the PRC clearly offers distinct ballistic advantages.
An index of the popularity of the 6.5 PRC as in the number of rifle models offered in the caliber is truly mind-boggling. After many hours on the Internet, I found that there are at least 22 different companies that list rifles chambered for the 6.5 PRC, with many variations and sub-models. I’ve included a list of these firms and their many models. No doubt I have missed some, but it gives you an idea of the diversity available. Models are subdivided into “production” and “custom,” but as you might expect, there is considerable crossover between them. All use the S.A.A.M.I. standard twist rate of one turn in eight inches. Barrel lengths are usually 22, 24, and 26 inches, but some are as short as 20 inches, and in custom guns, you can have it your way.
It is heartening to see that many very economically priced rifles (in both chamberings) are available, so the shooter can get into this arena without breaking the bank. Stalwart companies like Ruger, Savage, and others offer high-quality, accurate rifles at down-to-earth prices. Plus, a huge selection of factory-loaded ammunition is available with specialized bullets designed for specific tasks. And the accuracy of this ammo is well proven. A comparison of 6.5 CM and 6.5 PRC factory ammunition that I have fired in my own rifles accompanies this article.
Both the 6.5 Creedmoor and the 6.5 PRC offer splendid combinations of accuracy, ballistic efficiency, and power in quality rifles at relatively moderate prices. So what is the prospective 6.5mm buyer to do? I recommend getting at least one of each!