Nitro Express rifles: a history
- Credit: Archant
Diggory Hadoke traces the lineage of the Nitro Express hunting rifle all the way back to the 1840s
The original ‘express’ rifles came out of the quest by riflemakers to create a rifle that could send a medium-to-heavy bullet as directly to its target as possible, delivering devastating energy upon impact and getting from point A to point B in as straight and flat a trajectory as possible.
Attempts to perfect this over the years can be divided into three eras. First, there was the ‘percussion era’, when muzzle loading placed certain constraints on rifling and bullet size relative to the bore, as well as favouring or hindering certain types of rifling. Next was the ‘breech-loading era’, when shooters were first able to load the cartridge into a chamber without having to negotiate two feet of rifled barrel to seat the bullet. Finally, came the ‘smokeless era’, in which the limitations of black powder were overcome and the power of nitro-cellulose powders transformed the characteristics of express rifles, generally making them smaller in calibre.
We encounter the term in its abbreviated form today when perusing ammunition lists or auction catalogues. A bullet may be listed as .450 NE (Nitro Express) or a rifle as a .577 BPE (Black Powder Express).
Muzzle-loading express rifles
Pushing a lead ball or conical bullet down a rifled barrel provides greater stability (and, therefore, greater accuracy) than pushing one down a smooth bore. The lands of the rifling grip the bullet and impart spin.
However, if the bullet is pushed too hard by a large powder charge, the soft lead is simply stripped by the rifling, and the benefit lost. Experiments with rifling included altering the depth of the grooves, the number of grooves and the twist rate. Experiments with bullets included varying the hardness of the lead (or alloy), altering the shape and length of the bullets, and even casting them to fit the grooves in the rifling. Today, we think of bullets as smooth-sided projectiles, but in the mid 19th century, they took many forms.
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John Dickson of Edinburgh was a pioneer of the ‘express’ concept and achieved impressive results. He built two-groove rifles in the 1840s, which were, in actuality, the precursor to express rifles, even if they were not called that at the time.
Dickson’s rifles were given two deep grooves with a twist of one quarter of an inch in thirty inches. The bullets were of cast lead and roughly the shape of a pear, with raised protrusions corresponding with the grooves in the bore.
The bullets had to be rammed carefully down the barrel to seat them correctly, making loading a relatively slow process, but once correctly seated, the benefits were obvious to a sporting or target shooter.
Dickson’s two-groove rifles were made both as single-barrel and double-barrel types and in bore sizes from 11-bore to 70-bore. However, it was not until the 1850s that the term ‘express’ was used to describe a rifle, and the coiner of the phrase was not John Dickson, but James Purdey, the second of his name (to borrow a Game of Thrones line).
Purdey’s two-groove rifle had a twist rate of just one turn in six feet. Purdey used a conical bullet with protruding wings, which fitted the two broad grooves that formed the rifling. Because the wings fitted neatly into the broad grooves and did not strip, even when propelled by heavy charges, the result was a long point-blank range, flat trajectory and a high bullet-speed-to-weight ratio. Purdey likened it to an express train, because it went straight and fast to its destination. After Purdey built their first express rifle in 1851, the term gained traction and became universal.
Black-powder express rifles
Leap forward in time, and express rifles moved into their next phase of development, when percussion gave way to breech-loading with the introduction of the pin-fire in 1851 – although practically speaking, the change didn’t take place until the mid 1860s, when breech-loaders finally won the argument and the production of muzzle-loaders fell off significantly.
The black-powder express cartridges for rifles are legionary and start with fairly small bullets of around .360, moving through .400, 450, .500 and, finally, .577. A number of gunmakers developed proprietary chamberings in these calibres, designed to deliver a flat trajectory, high velocity and a long point-blank range.
This was especially advantageous for users of double rifles, which were often used in cover, where a rapid, shotgun-like mount brought the rifle to the shoulder for a quickly taken shot at a moving, or fleetingly seen, quarry (one which was often dangerous). The hunter wanted to be able to look at his target, engage it and kill it without the necessity of adjusting the sights or allowing for range and bullet drop.
One must remember that black-powder express rifles in these calibres were primarily suited to the hunting of medium game, such as red deer and sambar, and soft-skinned dangerous game, such as tigers and bears – though the larger ones were often employed against heavier animals.
Black-powder express rifles were most effective at ranges of up to about 250 yards. Compare a black-powder express .500 with an 8-bore rifle: the former fired a 380gr bullet at just over 1,600 fps and penetrated 19 boards at 40 yards (according to the 1883 Field Trials); the latter threw an 875gr ball at around 1,400 fps and penetrated the same number of boards. However, the double eight weighed 13½lb, whereas the .500 weighed just 9lb.
Nitro Express Rifles
When smokeless powders, with their increased power to move a bullet at speed, became available, everything changed. The real game changer was cordite, the double-base propellant which arrived in the late 1880s and revolutionised the nature of sporting rifles – express rifles included.
Suddenly, instead of muzzle velocities of 1,400-1,600 fps, new .500 and .450 rifles could now achieve 1,900-2,150 fps with bullets from 350 to 570gr in weight. The difference in performance made old-bore rifles obsolete and the revitalised .450 calibres, once considered best suited to deer, became high-performance dangerous game killers.
A good indication of the improvement in performance that cordite offered is the .577 Magnum Express black-powder rifle, one of the most powerful BPE cartridges ever devised. It threw a 502gr conical bullet at 1,530 fps from a double rifle, while the .500 Nitro Express, loaded with cordite and a heavier 570gr bullet, managed 2,150 fps. The energy delivery difference between the two is huge.
Today, if you order a new rifle from Westley Richards or Holland & Holland for the purpose of hunting animals such as buffalo, it will be a Nitro Express in .470, .500 or .577. The developmental lineage of that rifle can be traced right back to the 1840s.