Cartridge Board

Everyone has heard of this hot, relatively new 6.5mm cartridge. It has gained popularity faster than any other round, excepting those adopted by the U.S. military. Most every rifle made or imported chambers it. 

The chronicles tell us the concept of a cartridge to replace the 7.62x51mm (308 Winchester) for target applications was first discussed at the 2007 Camp Perry matches. Hornady ballistician/engineer Dave Emary was one of those involved. It doesn’t seem like much new ground was plowed, except for wanting a caliber smaller than thirty. The rest – lighter recoil, flatter trajectory and better accuracy – have been wanted ever since the first paper target was printed. The first Hornady 6.5 Creedmoor factory ammunition came out in June 2008.

Yet the existence of this cartridge predates 2007. In the early 1960s, a personable chap sometimes shot on our northern Illinois gun club range. He had retired from the Olin (Winchester) ammunition plant at East Alton, Illinois, and always had something interesting to show. One time, it was a box of unheadstamped cartridges. All were simply 308 Winchester necked to calibers from .17 to .35 because Winchester had been contracted to develop a replacement for the 30-06. When the final case design was approved, it was necked to all calibers. Why? Who knows. These were definitely the first necked-up or down 308 Winchester wildcats, including the 6.5mm-308 and later popular 7mm-308 round.

Before the new 7.62x51mm was announced, Winchester received the Army’s permission to release the cartridge as a sporting round. This was August 1952; the cartridge was the 308 Winchester.

As soon as wildcatters got hold of the 308 case, they necked it to all calibers, including metric. Such a frenzy had not been seen before. With surplus Mauser M98 actions selling for $17 to $25, many serious riflefolk who had only read about wildcats and custom rifles found themselves owning one or two.

Both the 308 and 7mm-308 became popular with metallic silhouette shooters. Meanwhile, Winchester had released the 6mm-308 (243 Winchester) and 35-308 (358 Winchester) in 1955. The 1955 Winchester catalog shows the great M88 lever action chambered for 243, 308 and 358; indeed, the rifle was designed for them. Unfortunately, Winchester then ceased the introduction of new cartridges on the 308 case.

The most hunted big game animals in the U.S. are deer. Winchester and gun writers sold the 243 as a deer and varmint round. It took a while, but those who killed a few deer with it found it was a good varmint round. The 308 worked far better but kicked like a ’06. Something in between was needed.

The difference between the .308 bullet diameter and the 243 bullet diameter is .065 inch. That’s a lot. About in the center is .277 inch, that of the .270 Winchester. The company was not about to make competition for its full-length 270. The 7mm-308 was too close to the .308, making the 6.5-308 next in line. Given the popularity of various 6.5mm rounds in Europe, Africa and India since at least 1890, it should have been introduced as the 6.5mm-308 or 6.5mm Winchester, but nothing was done. A great chance was missed, and the M88 disappeared long before its time.

Wildcats on the 308 case were not uncommon on rebarreled M88s and Savage M99s for maybe twenty years. During this time, bolt actions only long enough for the 308 and silly-short 16- to 18-inch barrels gained popularity for some reason. This grew to the point that Remington decided new cartridges for the little rifles were needed, wisely looking back to the 308 Winchester wildcats. The 7mm-308, renamed the 7mm-08 Remington, was announced in 1980. As a deer cartridge, it replaces the 308 Winchester, showing almost equal energy and a bit flatter trajectory to 300 yards. Remington repeated its performance by introducing the 6.5-308 wildcat in 1997, calling it the 260 Remington. Powder capacity was the same as the 6.5x54mm Mannlicher-Schonauer of 1903. That cartridge achieved quite a reputation at the time for taking large game using the 160-grain full-jacketed roundnose military load. Times have changed a bit. The first 260 Remington load used a 140-grain Core-Lokt bullet at 2,750 feet per second (fps). This gave slightly greater energy out to 300 yards than the 243 Winchester at the cost of a couple of inches of trajectory. Does this make it a superior deer round? Well, probably.

Now, considering the fact that the 6.5 Creedmoor case is almost a 260 Remington, what have we got? Basically, a case that is some 0.1 inch shorter than the 260 Remington, has imperceptibly less body taper and a shoulder angle increase from 20 to 30 degrees. Powder capacity of the 6.5 Creedmoor is a couple percent less than the 260 Remington, but the large number of bullets being loaded in both rounds makes that insignificant.

The 6.5 Creedmoor, when loaded with hunting-type bullets in either factory rounds or handloads, is nothing more or less than a 260 Remington. Maximum Average Pressure (MAP) for the 6. 5 Creedmoor has been set at 62,000 pounds per square inch (psi), although factory loads are said to be 5 to 6 percent below this in deference to semiautomatic rifles.

MAP for the 260 Remington is 60,000 psi.

In the 1960s, a benchrest group in Pennsylvania was shooting at 1,000 yards. Cartridges were wildcats such as the 6.5-300 Weatherby, Wright and Hoyer. Five-shot groups using Sierra and Norma match bullets could be covered with the palm of a hand.

Bullets today are better than ever. Thanks to chronographs that measure velocity along the bullet’s path, variations in ogive and base shape can be tried to see which moves through the air best. Thus, Hornady and a couple of others now produce the most accurate target bullets ever made. They precisely fit the Creedmoor’s chamber throat, which has about 0.2 inch of freebore and another 0.2 inch of 1.5-degree tapering leade.

Accuracy (100-yard grouping) is another matter. Custom target rifles group near 0.5 inch with factory target loads. Hunting rifles, however, perform no differently than the same modern rifles in 243, 7mm-08 or 308, grouping from about 0.85 to 1.3 inches with factory or handloads.

Speaking of handloading, the cost of factory ammunition will push many 6.5 Creedmoor owners in this direction. Components, especially empty cases, are often hard to find. However, good old Starline, the outfit that makes empty cases for handloaders and not sweatshirts or pocket knives, has 6.5 Creedmoor brass in stock. Also, Starline has 6.5 Creedmoor brass pocketed for both large and small rifle primers. 

A few words should also be said about long-range (400 yards plus), big-game shooting brought on by the 6.5 Creedmoor and a few others firing high ballistic coefficient, low drag, supposed hunting bullets. Devices such as laser rangefinders and light and wind meters, etc., seem to make a miss impossible. Yet they happen on rifle ranges many times a day. So, it doesn’t matter if it’s the last ten minutes of the last day of the season and the only living things seen in the woods during a week of hunting were Mexican wolves, spotted owls and illegal aliens. Chances of dropping an animal where it can be found immediately are slim. It seems unethical.

I’m sorry if this report is not as positive as all others. Seventeen years of use have shown the 6.5 Creedmoor to be an excellent long-range target cartridge firing special bullets in carefully made rifles. In normal hunting rifles, it’s quite ordinary, producing a little more energy than the 243 Winchester. Perhaps that makes it better. 

There is one aspect where the little 6.5mm stands above everything else. It has forced gunwriters and copy editors to learn how to spell the word “Creedmoor.”