Metallic Cartridge Nomenclature
By Chuck Hawks
Cartridge nomenclature has been haphazard at best, particularly in North America. Since the invention of self-contained ammunition, cartridges have been named in accordance with certain general customs in North America, Europe and the UK, but there have been many exceptions to these general rules. Here is how some of the common rifle and pistol cartridges got their names.
North American rifle and pistol cartridges
In the days of black powder, most North American centerfire metallic cartridges were described by their nominal caliber (the bore diameter of the barrel) and the powder charge they contained. Thus the .45-70 was a .45 caliber rifle cartridge that, in maximum loads, was powered by 70 grains of black powder. The .44-40 was a .44 caliber combination rifle and pistol cartridge charged with 40 grains of black powder.
Sometimes the bullet weight was added to the name, as in .45-70-405. That would be a .45-70 cartridge loaded with the standard 405 grain bullet. The .45-70-500 was the same cartridge loaded with a 500 grain bullet.
This basic system worked pretty well until the advent of smokeless powder. For while the energy per grain of different brands of black powder is essentially the same, smokeless powder can be manufactured in a nearly limitless number of variations. For example, the energy per grain of IMR 3031 powder is completely different than the energy per grain of Bullseye powder.
Early smokeless powder cartridges, such as the .30-30 Winchester and .30-40 Krag were, in fact, named following the old system. The .30-30 was originally loaded with 30 grains of the then new smokeless powder, and the Krag was loaded with 40 grains of smokeless.
However, it was soon realized that including the nominal powder charge in the name of smokeless powder cartridges was meaningless and potentially dangerous. So smokeless cartridges soon came to be named for their nominal bore diameter and the company that introduced them. This is how such familiar rifle cartridges as the .270 Winchester and .300 Savage were named. Sometime in the 1950's it became fashionable to name cartridges for the groove (or bullet) diameter. This is how the .308 Winchester (a .300 caliber cartridge by bore diameter) and .338 Winchester Magnum (a .330 cartridge by bore diameter) were named. Ditto the .357 Magnum revolver cartridge (a .35 caliber cartridge by bore diameter).
Today the groove diameter/bullet diameter is the most common method by which modern North American cartridges are named. The .243 WSSM, for example, has a groove diameter of .243" and uses .243" diameter bullets. Conversely, the .300 WSM was named for its bore diameter, just like the old .300 H&H Magnum of 1920. The Swedish .308 Norma Magnum was named in the North American fashion for its groove diameter.
Many cartridges have been named for neither their bore nor groove diameters. The .280 Remington has a bore diameter of .277" and a groove/bullet diameter of .284". And the .260 Remington has a bore diameter of .256" and a groove/bullet diameter of .264". Probably the names of these two cartridges were chosen because the sales people at Remington thought that customers would like even numbers like .260 and .280 better than less common numbers like .264 or .284. Along the same lines, the .340 Weatherby uses standard .338" bullets, and the .460 Weatherby uses standard .458" bullets.
When sales of the .280 languished, Remington tried changing its name to "7mm Express Remington." That name proved to be even less popular than .280, and Remington eventually reverted to the original ".280 Remington" moniker.
The bullet diameters of some popular cartridges are considerably overstated. The .380 ACP uses .355" bullets, the .38 Special uses .357" bullets, and the .44 Magnum uses .429" bullets. It is common to find the bullet diameter of pistol cartridges overstated.
One that is not overstated is the .41 Remington Magnum; its bullet diameter is actually .410. An oddity is the .38-40 Winchester, an old black powder cartridge that actually uses .40 caliber bullets, not .38 caliber bullets. It should have been called the ".40-40 Win."
A number of American cartridges since WW II have used metric designations for their bullet diameters. The cartridge that logically should have been named the ".280 Remington Magnum," since there was already a .280 Remington, was actually named the 7mm Remington Magnum, and went on to become the world's most popular magnum cartridge. When the fine .244 Remington didn't win customer acceptance under that name, it was renamed the "6mm Remington" and sales picked up.
A metric designation did not help the sales appeal of the cartridge that could have been called the ".32 Remington Magnum," (the original .32 Remington was introduced in the early years of the 20th Century), but was actually named the 8mm Remington Magnum. It has never caught on.
Winchester's first fat, short action, rebated rim cartridge was given a proper American name, .284 Winchester, but it never gained wide acceptance. In an attempt to capitalize on the cachet of a metric designation, the latest fat, short action, rebated rim Winchester cartridge that uses .284" bullets was introduced as the 7mm WSM. Only time will tell if this marketing ploy will be successful.
Other cartridges have been named in other ways. The famous .30-06 cartridge was designed for a .30 caliber bore and was adopted by the U.S. military in 1906. The 7mm-08 Remington has a 7mm bore and is based on a necked-down .308 case. The .25-06 has a .25 caliber bore and is based on a necked-down .30-06 case. These names reflect the cartridges' parentage.
Lou Palisano and Ferris Pindell designed the well known .22 and 6mm PPC bench rest cartridges; "PPC" stands for "Palisano-Pindell Cartridge." The .257 Roberts was introduced by Remington, but was named for its designer, Ned Roberts. The 7-30 Waters was designed by Ken Waters and introduced by Winchester. The .35 Whelen, standardized by Remington, got its name in a similar manner. The 7mm STW (for Shooting Times Westerner) was designed by Layne Simpson, a writer for Shooting Times magazine. All of these cartridges started life as wildcats and their names had become widely known before their standardization as factory loaded cartridges.
The .22-250 Varminter got its handle from J.E. Gebby, who trademarked the name ".22 Varminter" for his wildcat varmint cartridge back in the 1930's. Other wildcatters simply called it the .22-250 because it was based on a necked-down .250 Savage case. When Remington standardized the round in 1965 they added their name, calling it the .22-250 Remington. Lots of shooters still call the cartridge the Varminter, though.
The .250-3000 is a standard .25 caliber cartridge (bore diameter .250), and it was the first factory loaded cartridge to offer a muzzle velocity (MV) of 3000 fps. Its name is intended to both promote and capitalize on its high velocity. So was the name of the .220 Swift, actually designed by Winchester technicians, and the .224 Rocket from Weatherby. Other cartridges with names chosen to catch the attention of consumers (much like the names chosen for automobile models) include the .22 Hornet, .221 Fireball, .218 Bee, .219 Zipper, and the Remington Ultra Mag series of cartridges. One can only conclude that North Americans have shown a good deal of creativity in naming their cartridges.
European rifle and pistol cartridges
Meanwhile, in Europe, cartridges have generally been named for their nominal bore diameter and their case length in millimeters (rounded off). One millimeter equals 0.03937 inch. Thus "7x57" indicates a cartridge for a 7 millimeter (or approximately .276") bore with a case length of 57 millimeters. Our familiar .308 Winchester is called the 7.62x51 in Europe, and that is also its NATO military designation. It has a 7.62mm (or .300") bore diameter and a case 51mm long.
An "R" suffix indicates a rimmed case (i.e. 7x57R). Otherwise the case is assumed to be of rimless style. For example, 5.6x36R is the European designation for the American .22 Hornet, which has a rimmed case.
Sometimes the designer or company of origin is tacked onto the end, as in "6x62 Freres." The Germans added a "J" to the suffix of their 8mm Mauser round to indicate an infantry cartridge, which resulted in that cartridge being known as the 8x57J. Later an "S" was added to indicate the use of a new spitzer bullet in a cartridge originally loaded with a round nose bullet. Thus the "8x57JS" cartridge used in the Mauser 98 military rifle with which the Germans fought two World Wars.
The European system is basically reasonable, but they are actually not much better than the North Americans when it comes to accurately describing the bore of their rifles in the name of their cartridges. For example, the rifles for the original 8x57J Mauser cartridge actually used 7.9mm (.318") bullets. It wasn't until the advent of the 8x57JS cartridge that the 8mm Mauser adopted standard 8mm (.323") diameter bullets.
And Europeans have repeatedly described .22 caliber cartridges as both 5.56mm (as in the 5.56x45 NATO military cartridge) and 5.6mm (as in the 5.6x50 Magnum). Both use .224" bullets, the same as standard North American centerfire .22 cartridges.
Europeans often label .25 caliber cartridges (.250" bore and .256-.257" groove diameter) "6.5mm," which is actually .26 caliber (.256" bore and .264" groove diameter). The metric nomenclature for the .25-35 WCF, which uses standard .25 caliber (.257") bullets, is 6.5x52R. True 6.5mm cartridges, such as the 6.5x55 SE, use .264" bullets.
European handgun cartridges are likewise named for their bore diameter and case length. The famous 9x19mm pistol cartridge, which North Americans call the 9mm Luger, is a typical example.
British rifle cartridges
The British have their own somewhat unique system of cartridge identification. Like most American cartridges, British sporting rifle cartridges have been named for their bore diameter, and sometimes their groove or bullet diameter, usually followed by a manufacturers name.
They have also freely (and loosely) translated Continental European cartridges into their system. Thus the cartridge known the world over as the 7x57mm Mauser became the .275 Rigby in the UK, and rifles so marked are still turned out by the Rigby firm. These rifles shoot regular 7mm Mauser ammunition using .284" bullets. When the British appropriated the 9.5x57mm Mannlicher-Schoenauer cartridge they renamed it the .375 Rimless NE (2 1/4"). Holland's .244 Magnum actually uses standard 6mm (.243") bullets, as did their earlier .240 Magnum. The British seem to have been no more accurate in naming their cartridges than the Americans or Continental Europeans.
The term "Express" was often used to indicate higher than normal velocity, usually the product of a lighter bullet loaded in some established cartridge. The .577 Express (a black powder cartridge) would be one example.
When smokeless powder (Cordite or nitro powder to the British) became available, the word "Nitro" was added to the name of the earlier black powder express cartridges upon their conversion to the new propellant. The example in the paragraph above thus became the .577 Nitro Express when loaded with smokeless powder. "Nitro Express" is often abbreviated "NE."
Often the case length was included in the cartridge nomenclature, such as ".450 NE 3 1/4-inch." If that cartridge were necked-down to accept .40 caliber bullets it would become the .450/.400 NE 3 1/4-inch. Opposite from American practice, the British put the original cartridge size in front of the new size.
If a cartridge is available in both rimless and rimmed forms, the rimmed form is termed "flanged" and the rimless version "rimless." For example, the rimmed version of the famous .375 Belted Rimless Magnum (or .375 H&H Magnum) is called the .375 Flanged Magnum. The .375, by the way, is named for its groove diameter rather than its bore diameter.
Some British cartridges are known by more than one name, the .375 H&H mentioned in the paragraph above is one example. The .404 Jeffery is another, as this famous cartridge is also known in the UK as the .404 Rimless NE. Its case forms the basis, in much reduced length, for the Winchester WSM and WSSM lines of cartridges, and also the Remington Ultra Mag and Short Action Ultra Mag (SAUM) series.
British sporting rifle cartridge design was at its peak before the First World War. After the Second World War the British gun trade fell on hard times, due primarily to the dissolution of the British Empire and government interference. (The various socialist Labour Party governments have basically tried to stamp out the private ownership of firearms in the UK.) Kynoch, the British ammunition trust, stopped loading commercial ammunition in the 1960's. Most of the famous British African cartridges became obsolete, and the introduction of new cartridges practically ceased after the 1955 debut of the .244 Holland & Holland Magnum Belted Rimless, which failed to attract an international following.
But not entirely. In 1988 Holland and Holland partnered with Americans Jim Bell and William Feldstein to introduce the .700 Nitro Express cartridge and rifles in which to shoot it. Rigby introduced a new .450 Rigby cartridge in 1995, and in 2003 Holland & Holland announced a pair of new big bore cartridges, the .400 H&H Magnum Belted Rimless and the .465 H&H Magnum Belted Rimless. The name Kynoch has been resurrected and ammunition is once again being loaded for many of the classic British Nitro Express rifle cartridges in the UK. Thankfully, and unexpectedly, there appears to have been at least a modest resurgence of the British firearms and ammunition industry.
Copyright 2003, 2016 by Chuck Hawks. All rights reserved.