Nitro Express – the British had it right – by Johan van Wyk

The ancestry of many of the Nitro Express cartridges was firmly rooted in the black powder era. Here, examples of the .577 NE (3") and .500 NE (3¼") cartridges are shown together with their black powder forebears. Note how the later, cordite-loaded cartridges are loaded with jacketed bullets whilst the earlier black powder versions are loaded with soft lead bullets. Although not readily apparent from this photograph, the brass cases of the Nitro-powered cartridges are also considerably thicker in order to withstand the increased chamber pressure generated by cordite.

The ancestry of many of the Nitro Express cartridges was firmly rooted in the black powder era. Here, examples of the .577 NE (3″) and .500 NE (3¼”) cartridges are shown together with their black powder forebears. Note how the later, cordite-loaded cartridges are loaded with jacketed bullets whilst the earlier black powder versions are loaded with soft lead bullets. Although not readily apparent from this photograph, the brass cases of the Nitro-powered cartridges are also considerably thicker in order to withstand the increased chamber pressure generated by cordite.

As a group, the large bore British Nitro Express cartridges are in a class all by themselves. They were developed during a time when the British Empire stretched across the four corners of the globe, big-game hunting in Africa and India was at an all-time high, and Britain’s gun and rifle makers were at the forefront of developments in their field. In addition, many of the era’s well-known personalities and members of the then prevalent British and European royal houses considered hunting and shooting perfectly acceptable pastimes and regularly travelled abroad to hunt big game, armed with some of the finest firearms the British and European gun trades could produce.

The term “Express” was first coined by London gunmaker, James Purdey the Younger, in 1858 and was used to describe Purdey’s then new breech-loading rifles that fired bullets of lighter weight at velocities that were, for the time, groundbreaking. Purdey likened the bullets that his rifles fired to an Express train – they travelled fast with a flat trajectory. Over the years, the British gun trade adopted the word “Express” as pretty much a standard term and used it as part of the description of many of the black powder cartridges introduced during the 1880s and 1890s. These cartridges followed in the footsteps of the early Purdey breech-loading rifles in that they fired relatively lightweight bullets (when compared to those fired by the average muzzle-loading rifle of a generation or so earlier) at velocities somewhere around the 1500 fps mark. They were considered adequate for thin-skinned, non-dangerous game and even lion and tiger, but perhaps a bit on the light side for thick-skinned, dangerous game such as rhino and elephant, for which heavier artillery was needed. In 1898, though, something happened that doomed all of the black powder Express cartridges to obsolescence forever.

The year 1898 saw the introduction of a cartridge called the .450 (3¼”) Nitro Express by the venerated London firm of John Rigby & Co. The .450 (3¼”) NE (or .450, for short) fired a 480-grain bullet at 2050 fps powered by 70 grains of cordite, a double-based (nitro-cellulose and nitro-glycerine) propellant invented in 1889 and first loaded on a large scale in Britain in 1892 when it replaced the earlier black powder load for the British Army’s .303 Lee-Enfield service rifle. Cordite, which was also said to be “smokeless” because it generated considerably less smoke upon discharge than black powder, was capable of generating pressures far in excess of those attainable by black powder and the addition of the word “Nitro” in the .450’s designation was thus no mere wordplay but an indication that the new cartridge was in a ballistic class all by itself, generating almost 5000 ft/lbs of muzzle energy.

A disassembled British-made military .303 cartridge dating from 1940. In addition to the bullet and case, note the strands of cordite propellant as well as the over-powder wad which had to keep the propellant firmly in contact with the flash hole. Cordite’s bulkiness and unique characteristics as a propellant posed serious obstacles to rifle builders and ammunition makers alike during the early 1900s.

A disassembled British-made military .303 cartridge dating from 1940. In addition to the bullet and case, note the strands of cordite propellant as well as the over-powder wad which had to keep the propellant firmly in contact with the flash hole. Cordite’s bulkiness and unique characteristics as a propellant posed serious obstacles to rifle builders and ammunition makers alike during the early 1900s.

Hitherto, the only cartridges capable of producing such levels of energy were the mammoth black powder breech-loading rifles such as the 8-bore and their ilk, favoured by professional elephant hunters and others in need of the most powerful rifles available. The new Rigby cartridge offered the same energy but from a rifle that weighed less and was more comfortable to carry and shoot, and the rather unsurprising result was that it was an instant commercial success. In due course a host of Nitro Express cartridges followed in the .450’s wake, all the way up to the mighty .600, and all of them quickly carved out reputations for deadly efficiency on large, dangerous game. In spite of what some may claim, the recipe established by the .450, namely a bullet of approximately 480 grains leaving the muzzle in the region of 2100 fps or so, is the standard by which all dangerous-game cartridges are judged, irrespective of whether the recipe fits into any thumb-suck ballistic class or not. Thousands upon thousands of very dead animals and satisfied hunters over the last 113 years offer ample and unequivocal proof of this.

Effective though it was as a propellant, cordite did have a few drawbacks in the early days. The first and most obvious one was its bulk compared to other smokeless propellants of the day. Cordite was produced in bulky strands which took up considerable case capacity and just about all of the cartridges originally designed with cordite in mind therefore featured big cases with ample capacity to house a meaningful charge of cordite propellant. In later years, reloaders sometimes found it difficult to duplicate the ballistics of the original cordite loads with more compact modern propellants and new reloading techniques had to be developed for many of the large Nitro Express cartridges (the Gibbs .505 Magnum in particular springs to mind in this regard). Cordite’s bulkiness and any related headaches it may have caused to the cartridge designers of the Victorian era paled into significance when compared to some of the propellant’s other vices, however.When used in hot weather, cordite-loaded cartridges were susceptible to pressure spikes and, prior to the First World War, the British developed “Tropical” loads for many cartridges in an effort to keep pressures from rising to dangerous levels. With both the 3- and 3¼-inch versions of the .450/400 Nitro Express, for example, the normal load was 60 grains of cordite behind a 400-grain bullet. This worked just fine on the shooting ranges of England but often caused problems in Africa and India where the ambient temperature even during winter could be much higher. The Tropical load for the .450/400s with the same bullet therefore saw the cordite charge reduced by a full 5 grains to 55 grains, but the propellant’s propensity for increased pressure under hot conditions made up for the slightly decreased powder charge, and the slight loss of velocity was of no concern for the big-game hunters of the times. Cordite was thus a very temperature-sensitive propellant and, as we shall see, this factor played a significant part in the design of many of the big bore British elephant cartridges.

A spectacular double rifle by London maker James Woodward & Sons of circa 1889 vintage, chambered for the .450/400 (3¼") BPE. In contrast to rifles made in later years for Nitro cartridges, rifles like these were generally considerably lighter as they did not have to contend with the increased pressures and recoil generated by cordite propellant. As premier examples of the gunmaker’s art, best-quality rifles from this era are in a class all by themselves. (A Tonkin Collection)

A spectacular double rifle by London maker James Woodward & Sons of circa 1889 vintage, chambered for the .450/400 (3¼”) BPE. In contrast to rifles made in later years for Nitro cartridges, rifles like these were generally considerably lighter as they did not have to contend with the increased pressures and recoil generated by cordite propellant. As premier examples of the gunmaker’s art, best-quality rifles from this era are in a class all by themselves. (A Tonkin Collection)

Cordite’s third vice was that it burned at high temperature and was, in conjunction with the corrosive primers used in earlier British ammunition and steel-jacketed solid bullets, very hard on rifle barrels. The barrels of many fine old rifles often exhibit “cordite burn”, usually most noticeable in the first couple of inches ahead of the chamber, and this is directly attributable to cordite’s high burn temperature as well as the fact that the steel used for rifle barrels in the early 1900s wasn’t quite up to the standards we are used to today. This was hardly a concern during the early 1900s but it is definitely a factor to consider for today’s hunter on the lookout for a good used double rifle.

The British manufacturers of Kynoch ammunition had an absolute monopoly on Nitro Express cartridges from 1921 (when the British ammunition makers Eley Bros and Imperial Chemical Industries, Kynoch’s parent company, amalgamated) right up to 1963 when it ceased production of centre-fire rifle ammunition. Compared to the quality ammunition manufactured today for many of the Nitro Express cartridges by firms like Hornady, Federal and Norma, Kynoch may not have always represented the dangerous-game hunter’s ideal in terms of bullet design but it was still, for its time, good-quality ammunition that did at least go “bang” when called upon to do so. I recently chronographed a handful of pre-1939 Kynoch .500 (3¼”) NE rounds loaded with 570-grain soft-points and in spite of their age they still delivered a constant 2100 fps from a 26-inch barrel and a very healthy shove backwards without any hang- or misfires. I, for one, wouldn’t want to face an angry buffalo with 70-year-old ammunition but it certainly says a lot about the quality of Kynoch’s original manufacturing.

This .450 (3¼") NE hammer double rifle by John Rigby & Co, dating from 1900, is a wonderful example of an early Nitro double rifle. (J Bolt Collection)

This .450 (3¼”) NE hammer double rifle by John Rigby & Co, dating from 1900, is a wonderful example of an early Nitro double rifle. (J Bolt Collection)

In 1905, the British Home Department, in an effort to keep ammunition out of the hands of would-be rebels and insurrectionists, banned the use and importation of .450-calibre rifles and ammunition in India and the Sudan (in India, the ban was extended to the .303 as well). Although by this time a number of other Nitro Express cartridges were available as well, such as the 3-inch version of the .450/400, two different versions of the .500, the .577 and the mighty .600. The inevitable result was that the popular .450s, which had proven to be such a success, could henceforth no longer be exported to the territories in question. The British gunmakers scrambled to introduce a flock of new cartridges to take their place, or adopted other cartridges to offer their clients in place of the various .450s. Examples of proprietary cartridges introduced during this time include Holland & Holland’s .500/465 and Westley Richards’s .476, but in addition to these, almost all the makers chambered rifles for non-proprietary cartridges like the .475 No 2 (although WJ Jeffery & Co developed their own version of the cartridge which fired a slightly heavier bullet at reduced velocity), .500 and .577. Rigby themselves chose not to develop a new cartridge but adopted London gunmaker Joseph Lang’s .470 (which was introduced in 1906 as a result of the .450 ban and immediately released to the trade) as its standard dangerous-game double-rifle cartridge in place of their groundbreaking .450. The very first Rigby in .470, built as a boxlock non-ejector on a Webley screw-grip action, carried the serial number 17248. It was ordered from Rigby in 1905 by the Indian firm of Leslie & Anderson as a .450 but the order was changed as the ban came into effect and the rifle was subsequently delivered as a .470 in 1906.

The basic design of the double rifle is the weakest form of action when compared to falling-block single-shots and bolt-actions. It lacks the falling-block’s outright strength and rigidity and the bolt-action’s camming power and positive extraction, and is therefore much more dependent on ammunition loaded to acceptable pressure levels than its competitors. The British found this out the hard way early on. Some of the earlier Nitro Express cartridges such as the .450 and the 3¼-inch version of the .450/400 were Nitro-powered versions of earlier black powder rounds. In the black powder versions of these cartridges the walls of the brass cartridge cases could be made relatively thin on account of the modest pressures developed by the original black powder loads and the lightweight lead bullets they fired. However, when these same thin-walled cartridge cases were loaded with hefty doses of cordite and heavier jacketed bullets and fired in the tropics, disaster struck. The thin-walled cases couldn’t cope with the sudden pressure increase and often developed splits and stuck to the insides of rifle chambers. A stuck cartridge case renders even the most expensive double rifle as useless as a club when faced with an irate, homicidal animal at close range, and it’s fair to assume that both riflemakers and ammunition manufacturers alike received a few angry letters in the early days of the Nitro era from hunters who had near-misses with big animals due to ammunition problems. The cure for this problem was to make the walls of the cartridge cases much thicker, and the heavier cases were able to withstand the increased chamber pressure much better and extracted readily when called upon to do so. However, the addition of beefed-up cartridge cases only tells part of the story.

The basic design of the double rifle is weak compared to the falling-block single-shot or the bolt-action, and as a result double rifles are very much dependent on ammunition loaded to acceptable pressure levels to ensure positive extraction. Note the relatively modest size of the extractors fitted to this 1899-vintage best-quality Rigby sidelock double rifle, chambered for the .303 British. (J Bolt Collection)

The basic design of the double rifle is weak compared to the falling-block single-shot or the bolt-action, and as a result double rifles are very much dependent on ammunition loaded to acceptable pressure levels to ensure positive extraction. Note the relatively modest size of the extractors fitted to this 1899-vintage best-quality Rigby sidelock double rifle, chambered for the .303 British. (J Bolt Collection)

All the old British double rifle cartridges, even the straight-walled ones, followed a common recipe in that they were designed with thick rims in order to allow plenty of purchase for the extractors of double rifles. Coupled with this, the cartridge cases themselves were designed with a gentle but noticeable taper from the base of the cartridge towards the neck. Again, the reason for this was to ensure easy extraction. Thus, the combination of good basic design, heavy brass cartridge cases and modest loads of cordite combined to make the Nitro Express cartridges the unqualified success that they were, and are to this day. For some reason, the lesson in all of this appears to be lost on some of today’s manufacturers and history seems to be repeating itself to some extent with the odd whisper of modern bolt-action rifles chambered for straight-walled “Wonder Magnum” cartridges loaded to uncomfortably high pressure levels, giving sticky extraction (or even no extraction at all) cropping up far too often for comfort.

Many of the old Nitro Express cartridges are enjoying a new lease of life today. Ammunition for many of them is once again available from a number of sources, all loaded with bullets far superior to those of the 1920s. Modern primers and propellants have also improved by a few orders of magnitude and this, along with a proper understanding of and the use of over-powder wads to take up empty space in the cavernous cartridge cases that would previously have been occupied by strands of cordite, has ensured that the old British Nitro Express elephant cartridges are more effective today than they have ever been throughout their long history.

Even though modern technology has leant it a very welcome helping hand, it still goes to show that the basic recipe of the Nitro Express, perfected more than a century ago by a few nameless individuals slaving away at their workbenches in dimly-lit workshops in London and Birmingham, was exactly right. Long live the Nitro Express!

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