Overnight Success: 6.5mm Rifle Cartridges
By Chuck Hawks
I have been writing about the virtues of 6.5mm rifles and cartridges since 1999, before they became popular mainstream cartridges in the US. To paraphrase Ted Turner, "I was into 6.5mm before 6.5mm was cool."
I was introduced to the caliber by my late friend Gordon Landers, who at the time was a Guns and Shooting Online Editor. Gordon was a fan of the 6.5x55 and, after its introduction, the .260 Remington, which became his favorite hunting cartridge in the Remington Model 700 LSS Mountain Rifle. Gordon also owned and experimented with a 6.5mm Remington Magnum rifle, but his favorite calibers remained the .260 and 6.5x55.
Anyway, sometime in the late 1990s, Gordon talked me into buying a nice Carl Gustaf Model 1896 Swedish Mauser that was languishing at a local gun shop and soon I was hooked on 6.5mm cartridges and began writing articles about them. I later gave that Swedish Mauser along to another Guns and Shooting Online writer, but by then I owned hunting rifles in 6.5x55mm and also .260.
The proven killing power of classic 6.5mm cartridges, such as the 6.5x54mm Mannlicher-Schoenauer (circa 1900), 6.5x57mm Maser (circa 1894) and the fabulous 6.5x55mm SE (circa 1896) cannot be denied. They do their job with minimum muss and fuss (recoil and muzzle blast) and with standard jacketed bullets. Seldom are premium bullets required, due primarily to the excellent sectional density (SD) of the 140-160 grain bullets that made the classic 6.5mm cartridges famous, particularly in Europe and Africa.
The 6.5x54 M-S and 6.5x57 Mauser are not common in the US, but starting in the 1950s, surplus Swedish M96 Mausers became available in the US and American shooters discovered the 6.5x55 cartridge. RCBS reports it has consistently been among their Top 30 best selling reloading dies for a long time.
Even before the current "overnight" popularity of the .264 inch diameter bullet, American manufacturers occasionally tried to interest US shooters in 6.5mm cartridges. The .264 Winchester Magnum, introduced by Winchester in 1958 in a Model 70 rifle dubbed the "Westerner," is one example.
As originally loaded, the .264 Mag. drove a 140 grain bullet at a muzzle velocity of 3200 fps from the 26 inch barrel of an M-70 Westerner rifle. The .264 never became a big seller, although it endures to this day. At the time, it was criticized as over-bore and a barrel burner, not to mention loud with a sharp kick. Today, new long range cartridges in several calibers (including 6.5mm) are much worse than the .264 in these respects and the shooting press doesn't even mention it.
The 6.5mm Remington Magnum of 1966 was that Company's attempt at a 6.5mm short magnum. It offered performance comparable to the famed .270 Winchester in a short action rifle. Apparently, not many folks though saving 1/2 inch of action length was worth the effort.
Meanwhile, in Europe, the 6.5x68mm Schuler (RWS) had been providing ballistics comparable to the two American magnums since about 1940. Its case capacity is similar to the .264 Win. Mag. Despite the interruption of WW II, it became a reasonably popular cartridge and remains so today.
The 6.5x65mm RWS (circa 1988) is a later European cartridge with very similar performance to the 6.5x68mm. Apparently our European friends are no more resistant than their US counterparts to duplicating existing ballistics in new bottles in an attempt to stimulate sales.
To bring this condensed 6.5mm timeline up to date, Remington adopted the wildcat 6.5mm-08 wildcat as the .260 Remington in 1997. The .260 was designed as a short action hunting cartridge and basically duplicates the performance of the 6.5x55 in a slightly smaller case. That same year, A-Square standardized the old wildcat 6.5mm-06.
In 2001, Norma standardized the wildcat 6.5-284. Loaded to 1000 psi higher maximum average pressure (MAP) than the 6.5mm Rem. Mag., the 6.5-284 became a popular F-Class match cartridge.
Since 2002, we have had a bunch of new 6.5mm cartridges. These include the 6.5mm Grendel (circa 2002), a very short 6.5mm cartridge of modest performance intended for use in AR-15 actions; ballistics are similar to the old 6.5x50mm Jap. service cartridge. For hunters, CZ offers their Model 527 bolt action in 6.5mm Grendel.
The 6.5x47mm Lapua (circa 2006) is an obscure, short action, bench rest and match cartridge that, as far as I can tell, has not caught on with hunters. The 6.5mm Creedmoor (circa 2008) is another short action match cartridge that is loaded to higher pressure to compete with the .260 and 6.5x55, which have greater case capacity. Heavily promoted by Hornady, the 6.5 Creedmoor has successfully caught the attention of hunters and rifle manufacturers.
In the way of recent 6.5mm Magnum cartridges, we have Hornady's 6.5mm PRC (circa 2017), a short action, combination long range match and hunting cartridge. The powerful, standard length .26 Nosler (circa 2013) has even greater case capacity (and shorter barrel life) than the .264 Win. Mag.
The ultimate in over-bore 6.5mm cartridges (so far) is the 6.5-300 Weatherby Magnum (circa 2016). This is based on a necked-down .300 Wby. Mag. case and launches a 140 grain A-Frame bullet at a muzzle velocity (MV) of 3395 fps.
After the introduction of the 6.5mm Creedmoor, gun writers of all sorts, print and online, seem to have discovered the 6.5mm caliber and began extolling its virtues. Widely used in Europe and Africa for over 120 years, 6.5mm cartridges and rifles of all sorts are suddenly an overnight success in the USA!
At this point I think a brief digression to define rifle action lengths is appropriate. In hunting rifles, particularly bolt action rifles, there are a few very short actions, such as the CZ 527. With an action length similar to an AR-15 self-loading rifle, these are chambered for cartridges on the order of the .223 Remington and 6.5mm Grendel (cartridge overall length 2.260 inches).
"Short action" generally means designed for cartridges with a maximum cartridge overall length (COL) no longer than the .308 Winchester (2.810 inches). In standard 6.5mm cartridges, this would include the .260 Remington, 6.5mm Creedmoor and 6.5-284 Norma. Short action magnums include the original 6.5mm Rem. Mag. and recent 6.5mm PRC.
"Standard" length actions (sometimes called "long actions" by manufacturers who do not offer a true magnum length action) are designed to accommodate cartridges as long as the .30-06 Springfield (3.340 inches). The 6.5mm-06 A-Square is an example of standard length cartridge. Standard length magnums include the .264 Win. Mag., 6.5x68mm and .26 Nosler.
"Magnum," or "Long Magnum" actions are usually intended for cartridges as long as the .375 H&H Belted Magnum (3.60 inches). The 6.5-300 Wby. Mag. is an example of such a 6.5mm cartridge.
Seldom seen these days is an intermediate length action designed specifically for cartridges between the .308 and .30-06 in length. The 6.5x55mm and 6.5x57mm are ideally suited for an intermediate length action. Mauser produced a commercial Model 98 intermediate length action before WW II.
Today, intermediate length cartridges are normally chambered in rifles with standard length actions, which are about 0.1 to 0.2 inches longer than actually necessary. This is not altogether a bad thing, as (unlike short action cartridges and rifles) it gives reloaders greater flexibility in bullet choice and seating depth, even with the longest 156-160 grain 6.5mm bullets.
The Maximum Average Pressure for the 6.5x55 was standardized by SAAMI in the US at an unusually low 51,000 psi, in deference to long obsolete (and notoriously weak) Norwegian Krag service rifles. (The M96 Swedish Mauser service rifle is much stronger than the Krag.) 6.5x55 ammunition loaded to more realistic European CIP sporting standards is loaded to a MAP some 27% higher. Anyone with a Mauser 98 or more modern sporting rifle can shoot full power loads without a problem. For comparison, SAAMI specifies a MAP of 62,000 psi for the 6.5 Creedmoor and 60,000 psi for the .260 Remington, yet all three of these cartridges are offered in equally strong, modern rifles and can safely be loaded to identical MAPs.
Magnum cartridges are usually loaded to a higher MAP than standard cartridges. For example, per SAAMI specifications, the .264 Win. Mag. can be loaded to 64,000 psi and the .26 Nosler to 65,000 psi. Obviously, a fair comparison of cartridge performance requires that they be loaded to the same MAP.
As the history above illustrates, while there are many recent 6.5mm cartridges, very few of them actually bring anything new to the table in terms of performance. Designed to operate in short action rifles, the .260 Remington is based on a slightly smaller case than the earlier 6.5x55 and the even newer 6.5 Creedmoor is based on a slightly smaller case than the .260. Loaded to the same pressure, especially with 140 grain and heavier hunting bullets, the 6.5x55 can outperform the .260 by about 100 fps and the .260 can outperform the Creedmoor by 50-100 fps.
The 6.5x55 is the most versatile and flexible of these cartridges and, despite its age, it is a modern looking cartridge. (See illustration at top of page.) However, all three can launch a 140 grain hunting bullet (SD .287) at around 2700 fps at moderate pressure, muzzle blast and recoil. (140 grains is the bullet weight that put 6.5mm hunting cartridges on the map.)
These three cartridges can be pushed harder, but if you need more energy than provided by a 140 grain bullet at a MV of 2650-2700 fps, you would probably be better served by a larger caliber rifle. Practically speaking, no game animal can live on the difference between these cartridges, which implies that the .260 and 6.5 Creedmoor are redundant.
With long, heavy 156-160 grain bullets the greater case capacity and COL of the 6.5x55 gives it an advantage and in Scandinavia the 6.5x55 has been a very successful moose and even polar bear cartridge. For example, Norma of Sweden offers their 156 grain Vulkan bullet in 6.5x55 factory loads at a MV of 2644 fps. Back in the bad old days, D.W.M. Bell famously used the modest 6.5x54 M-S, shooting 159-160 grain RN-FMJ bullets (SD .328) at 2200-2300 fps, to harvest many African elephants for their ivory. Just sayin'.
Among short action Magnums, the 6.5mm PRC has slightly greater case capacity than the 6.5mm Rem. Mag. Hornady factory loads claim a MV of 2960 fps with a 143 grain hunting bullet. The Hornady reloading handbook shows maximum loads for the 6.5mm Rem. Mag. at 2900 fps with the same bullet. (24 inch test barrels in both cases.) The difference between the two cartridges is not enough to matter to a big game animal.
The standard length .264 Winchester Magnum has been throttled back by Winchester and Remington to a factory loaded MV of 3030 fps with a 140 grain bullet (24 inch test barrel). However, reloaders can exceed 3150 fps with 140 grain bullets in the .264 Mag. Its performance is similar to the 6.5x68mm Schuler when both are loaded to the same MAP.
The huge .26 Nosler is based on a .404 Jeffery elephant cartridge case necked-down and shortened to a COL of 3.340 inches. Nosler advertises a factory load MV of 3300 fps with their 140 grain bullets.
The even larger 6.5-300 Weatherby Magnum is based on a full length .300 Weatherby Magnum case necked-down. Weatherby factory loads with 140 grain bullets advertise a MV of 3304-3395 fps, depending on the specific bullet.
These super 6.5mm Magnums are all well and good, until you remember that the .264 Magnum was roundly criticized as being over-bore (meaning its bore diameter is too small to allow efficient burning of the volume of powder in the case in barrels 24-26 inches long) and a barrel burner, which it is. However, compared to the .26 Nosler and 6.5-300 Weatherby, the .264 Winchester seems conservative. You could conclude these 6.5mm Super Magnums have far exceeded the point of diminishing returns and get no argument from me.
All of the 6.5mm Magnums kick harder than the .260 and 6.5x55 and have increased muzzle blast. None of them kill any better, although they will kill just as well from farther away. Unfortunately, statistics show that when hunters shoot at game animals at distances exceeding 160 yards, even from a rest, the number of wounded and lost animals climbs alarmingly.
Longer range capability is, therefore, a snare and a delusion. The vast majority of hunters (this means you and me!) are better served by the 6.5x55 and .260 than any 6.5mm Magnum cartridge, or any long range match cartridge adapted for hunting with extra low drag (i.e. very long range) bullets. If your self image requires a magnum cartridge, the neglected 6.5mm Rem. Mag., based on the very first short magnum case, is probably the most reasonable.
Choosing a 6.5mm Rifle
If you favor a short action rifle, the .260 Remington is probably the way to go. If the brand of rifle you prefer is not offered in .260, but is available in 6.5mm Creedmoor, it is almost as good.
If a 1/2 inch longer receiver does not intimidate you, the 6.5x55 remains the world standard among 6.5mm cartridges and it is the obvious choice as an all-around cartridge. The ballistics for all of these cartridges are measured in 24 inch test barrels, but they perform well in hunting rifles with 22 inch barrels and reasonably well even in carbines with 20 inch barrels.
As for 6.5mm Magnums, they have never made a lot of sense to me, particularly those with greater case capacity than the 6.5mm Remington Magnum. Even the .264 Win. Mag. offers only about 100 fps MV advantage over the much more popular and widely distributed .270 Winchester with a 140 grain bullet. Any magnum rifle should have at least a 24 inch barrel to take advantage of its extra powder capacity and a 26 inch barrel is preferred, particularly for the .264 Win. Mag.
The outsized .26 Nosler and 6.5-300 Weatherby are completely over the top. These big case numbers sacrifice all of the fine qualities (deep penetration with standard soft point bullets, good killing power, modest recoil and muzzle blast, long barrel life) that made the 6.5mm caliber popular in the first place. As I mentioned earlier, if you need more killing power than the standard 6.5mm cartridges, you probably need a bigger caliber bullet, not just a bigger case for higher velocity.
If you order a Nosler Model 48 Custom rifle in .26 Nosler, be sure to specify a 26 inch barrel. Weatherby Mark V 6.5-300 Mag. rifles are supplied with 26 or 28 inch barrels, depending on the specific model.
The standard velocity 6.5mm cartridges on the order of the 6.5x55 and .260 are mild and effective Class 2 game hunting cartridges, particularly with spitzer bullets weighing about 140 grains. This is the bullet weight that made the caliber's reputation, due to its combination of excellent sectional density, ballistic coefficient and penetration. Recoil is mild in medium weight rifles and, consequently, most hunters can shoot them well. Ammunition is widely distributed and reasonably priced, as are bullets for reloaders.
Under favorable circumstances and with maximum loads using heavy for caliber 156-160 grain bullets, the 6.5x55, 6.5x57, .260 and similar cartridges have served adequately even on large Class 3 animals. Accurate bullet placement and deep penetration make these standard velocity 6.5mm cartridges far more effective killers than their modest paper ballistics might suggest.
Note: Full length articles about all of the cartridges mentioned in this article can be found on the Rifle Cartridges index page.
Copyright 2018 by Chuck Hawks. All rights reserved.