6.5 PRC: The "Just Right" 6.5mm Cartridge - SkyAboveUs - Outdoors
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6.5 PRC: The "Just Right" 6.5mm Cartridge

Author:

LJ Bonham is a semi-subsistence hunter, hunting magazine editor, and firearms enthusiast who lives in the Rocky Mountains.

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Thirty years ago, American shooters, for the most part, could care less about 6.5mm bullets or the cartridges which fired them. This reflected a situation which had existed since World War Two’s end in 1945. Other than the small cadre who understood and loved the 6.5x55 Swedish, post-war America remained a land dominated by .30 calibers and magnums.

A scant eleven years ago, in 2008, Hornady brought to market a curious beast. Dubbed the 6.5 Creedmoor, their brain child served but one, focused purpose—punch neat, tight grouped holes in faraway paper targets. Long-range match shooters had migrated away from the once gold standard .300 Winchester Magnum to both 6mm and 6.5mm diameter bullets to leverage those narrow slugs’ high ballistic coefficients and pamper their abused shoulders with less recoil. When a range session or match can burn up cartridges by the dozens or even hundreds, the .300’s ballpeen hammer smack gets a bit tedious, and your scores suffer.

For almost a half-decade, the Creedmoor stayed in the shadows, known to just the target match cognoscenti. Around 2015, or so, things changed. Long-range hunting had become all the rage fueled by Allied sniper exploits in Iraq and Afghanistan. A natural evolution occurred as the long-range hunters turned to the match world for innovations. Almost overnight, it seemed, the 6.5 Creedmoor became a media sensation and everyone had to have one.

A mere three years later, an even newer cartridge stole the spotlight from the Creedmoor. Hornady themselves developed what may become the perfect 6.5, the 6.5 Precision Rifle Cartridge, or PRC.

6.5 PRC vs. 6.5 and 6 Creedmoor

The 6.5mm Advantage

6.5mm bullets aren’t new. Gun designers have known their advantages since the late 19th century. The 6.5’s occupy the sweet spot between smaller and larger bore sizes. Their high ballistic coefficients combine with high sectional densities to create a near perfect balance between trajectory and lethality. In short, they retain velocity, and hence energy, down range better than other calibers, and they drive deep into whatever they hit, such as a game animal. They can do the same, or more, work as larger bullets with less velocity and hence don’t require huge powder charges. This translates into lower recoil which improves a shooter’s accuracy, and accuracy is what kills game.

The 6.5mm Darkside

If 6.5mm bullets are so good, why would anyone use a bigger bore with all the attendant recoil? While a 6.5mm drives deep into an animal, it doesn’t make as wide a wound channel as a bigger caliber. When it comes to the larger game animals, elk, moose, kudu, eland, etc., simple efficiency is sometimes insufficient to cause a clean kill. A wide, heavy bullet imparts more trauma to tissue which surrounds the wound channel than a narrow, light one given similar placement if both expand the same percentage beyond their original diameter.

It is possible to drive a 6.5mm bullet fast enough to create the energy necessary for a humane kill on large game, but simple numbers belie the whole truth. According to experts who have conducted extensive field research on hunting bullets and their effectiveness, such as Nathan Foster at Ballistic Studies, hunters often observe the effects 6.5mm bullets have at reasonable ranges on medium-sized game and then erroneously infer they will produce the same results on larger species. Thus, they ask too much from these narrow needles. They often inflict superficial, indecisive wounds on game whereas a wider, heavier projectile, with its larger total wound cavity, would have dropped the animal is short order.

Remember, the venerable 6.5x55 Swedish got its deserved reputation as a moose and bear killer in Scandinavia where shots are taken well inside 100 yards on average. 6.5mm bullets provide little, if any, margin for error at extended ranges (500 or more yards) and require near surgical placement in an animal. A .30, .338, or even .375 caliber bullet which hits an inch or two off from the heart, for instance, still has a good chance it will create a hydrostatic shock wave wide enough to tear the major aortas or substantial heart muscle, whereas a 6.5mm bullet may not.

Things You Must Consider if You Build a 6.5 PRC Rifle

Enter the 6.5 PRC

So what’s all this have to do with the 6.5 PRC? In simple terms, it tries to do what so many other 6.5s have in the past (.264 Win. Mag. and 6.5 Rem. Mag.), but its more efficient case design reduces many problems the older rounds created.

Ballistics for the one factory hunting load now available for the 6.5 PRC is a Hornady 143 grain ELD-X bullet driven at 2960 fps, which gives 2782 ft-lbs. energy at the muzzle (40 ft-lbs. more than a 180 grain .308 Winchester). Downrange at 500 yards, it makes 2245 fps and 1601 ft-lbs. at sea level. This is near the 1500 ft-lbs. minimum impact energy most experts recommend for large game. It's a reasonable elk gun inside this limit, and out shoots the 6.5 Creedmoor on large game by 100 - 150 yards. The 6.5 PRC is a legitimate 700 yard deer dropper, though.

At 1000 yards, things unravel, with just 1644 fps and 858 ft-lbs left over. The 6.5 PRC is just not an ethical 1000 yard elk slayer. Period. No matter what some may think. Never mind the argument as to whether one should even attempt such high-risk shots.

The other problem the 6.5 PRC presents is barrel erosion. This cartridge is quite overbore, ie. the ratio between large case powder volume and narrow case neck diameter creates a plasma cutting torch inside a barrel’s throat. With a 143 grain bullet, the PRC’s overbore number is 1127. Compared to the 7mm Rem. Mag.’s 1326, the 6.5-284 Norma’s 1205, or the .264 Winchester Magnum’s epic 1447, the PRC looks quite good, but it is still well past the 1000 red line for overbore. These rounds are famous for barrel throat erosion. The .30-06, for example, is 915, and the barrel friendly .308 Winchester is 652. The 6.5 Creedmoor scores 850, and the tried and true 6.5x55mm is 912. Don’t expect a rifle chambered in 6.5 PRC to serve for decades without a few new barrels along the way if you shoot enough rounds per year to stay proficient at long range.

6.5 PRC in Its Element

Light at the End of the Tunnel

If there is so much wrong with the 6.5 PRC, why would it still become the best 6.5? While it will eat barrels, it won’t do it at near the other 6.5 magnums' rate. It also doesn’t suffer from the Norma’s rebated rim, so it feeds just fine in a magazine rifle. True, the Creedmoor is the most barrel friendly 6.5, but it can’t put reliable hurt on big critters much beyond 300 – 350 yards. The PRC has enough surplus case capacity to make loads with proper 6.5mm bullets in the 156 to 160 grain range a viable proposition, whereas the Creedmoor doesn’t. Hunters should lean toward these heavier bullets, not the target punchers’ 140 – 147 grain ones. The 6.5s are best served with these heavy bullets so their high sectional densities can offset narrow wound tracks. Dropping game is a much different proposition than the quest for top score in a match.

The 6.5 PRC is, for all intents, a short magnum and thus in a different class than either the 6.5x55 or 6.5 Creedmoor, but it has far better manners than all the other .264 caliber magnums out there. It has the lowest recoil in the magnum class, the least barrel wear (even if it is higher than the Swede or Creed), yet hits hard enough to drop elk at 500 yards and deer at 750 (which is much farther than the average hunter can make reliable hits). Thus the PRC overcomes the Creedmoor’s power and bullet weight deficits, and mitigates the magnums’ biggest faults (recoil, barrel wear). Once the smoke clears in the current 6.5mm fracas, the 6.5 PRC has the best chance to emerge the clear winner.

© 2019 LJ Bonham