Left to right: .256 Newton, 6.5x55, .260 Remington, 6.5mm Remington Magnum, .264 Winchester Magnum. Only the 6.5x55 has had lasting (although limited) popularity.

If you work the numbers with a ballistics program, as I did in the accompanying chart, it's easy to see that the 6.5mm looks pretty darned good. It holds up extremely well at distance and doesn't beat you up in the process. For instance, if you can get an aerodynamic 140-grain 6.5mm bullet up to about 3,000 fps--which, depending on barrel length and load, is possible in several 6.5mm cartridges--you will achieve a trajectory curve similar to a 140-grain bullet out of a .270 WSM at 3,200 fps.

Perhaps a better example is to compare a 140-grain 6.5mm at 3,000 fps against a similar 180-grain .30 caliber bullet at 3,200 fps. I can get 3,000 fps out of my .264 Winchester Magnum, and I can get 3,200 fps out of my .300 Weatherby Magnum. As you can see from the table, the trajectory curve is about the same, but in a 20 mph crosswind the 180-grain .30 caliber drifts about six inches more at 400 yards. And of course my .300 Weatherby is going to beat me up a whole lot more in the process. This is why inherently accurate 6.5mm cartridges such as the short, fat 6.5-.284 Norma have become a darling of the 1,000-yard crowd.

.264 Winchester Magnum Comparison
CALIBER BULLET WEIGHT (gr.)	MUZZLE		200 YARDS		300 YARDS		400 YARDS
	VELOCITY (fps)	ENERGY (ft. lbs.)	VELOCITY (fps)	ENERGY (ft. lbs.)	VELOCITY (fps)	ENERGY (ft. lbs.)	VELOCITY (fps)	ENERGY (ft. lbs.)
.270 WSM 140	3,206	3,195	2,758	2,364	2,550	2,021	2,351	1,718
Trajectory (in.)	__		0		-5.6		-16.4
.264 Win. Mag. 140	3,008	2,812	2,627	2,146	2,449	1,864	2,277	1,612
Trajectory (in.)	__		0		-6.2		-18.2
.300 Wby. Mag 180	3,200	4,093	2,669	2,848	2,426	2,353	2,196	1,928
Trajectory (in.)	__		0		-5.9		-17.8
Notes:	Data taken from QuickLoad and QuickTarget ballistic programs. All bullets are Nosler Partition to maintain similar ballistic coefficient

None of this is new, so why has the 6.5mm never achieved great popularity here in America? In part it's because of our .30 caliber culture, and in part it's because clear back in 1925 Winchester decided on an almost unheard of .277-inch bullet, creating the .270 Winchester. Had it opted for the very similar 6.5-06 instead (which was then and still is a reasonably popular wildcat) history might have been different.

But that's ancient history, as is the failure of the Newton Rifle Company, which took with it the .256 Newton. The failures of more recent 6.5mms can perhaps be tied to other factors. The .264 Winchester Magnum was an instant success that seemed destined for lasting stardom. However, original factory figures contained an awful lot of blue sky. The word got out, along with the rumor that the .264 (which is definitely somewhat overbore capacity.) was a barrel-burning S.O.B.

Then along came the 7mm Remington Magnum. The 7mm is admittedly a bit more versatile and able to strut its stuff quite well from a 24-inch barrel, while the .264 really needs two more inches. The 7mm Remington Magnum raced ahead, and the .264 became an also-ran.

Perhaps even more tragic is the fate of the 6.5mm Remington Magnum. It was introduced in 1966 along with the .350 Remington Magnum.These cartridges were ahead of their time--the first "short magnums" intended for .308-length actions.

But Remington introduced them in the Model 600 series carbines. In that guise, both gathered followings that were extremely loyal but small. In its light little synthetic-stocked Mohawk carbine, the .350 was legendary as a hard-kicker.

The 6.5mm actually did okay in its 18-inch barrel, coming pretty close to .270 Winchester performance. However, if you browse through a modern reloading manual you will discover the 6.5mm Remington Magnum is a tremendously efficient little cartridge. According to Nosler's latest manual, in a 24-inch barrel there are several powders that allow the 6.5mm Remington Magnum to outrun the .264 Winchester Magnum.

The jury is still out on the .260 Remington. It was championed by Jim Carmichel, as astute a rifle guy as ever lived, and it was touted for its exceptional inherent accuracy. But with factory loads I haven't yet seen a .260 that showed me much, and perhaps its biggest problem is that it so closely duplicates the performance of the superb and popular 7mm-08 Remington.