The ball/rifle cartridges are designed for shooting from rifles and are made in various versions in particular according to specifics of cartridge case. It took quite a long time to find a way for the right solution before the rifle cartridge got the look we know now.
The basic idea that motivated the development was elimination of lengthy and tedious time of loading through the muzzle and to assemble the bullet, powder and primer into one unit thus creating an integrated cartridge. The first integrated cartridge was patented in France in 1812 by the gunsmith J.S. Pauly.
Pauly´s initial cartridges were already very impressive as during demonstration shooting he was capable to shoot 22 shots within two minutes, this when compared with muzzleloader was almost miraculous performance. The first unified and self-contained cartridge attaining the mass use was the cartridge for the Dreyse needle gun (rifle utilising needle-like firing pin) from 1841. This cartridge still had a rather simple form of the paper roll joining together the bullet and powder charge. The primer had been fixed to the base of the bullet at the centre of the cartridge. Upon release of the trigger, the striker in the form of needle firstly pierces the cover (in the rear) of the cartridge then passes through the powder charge up to the primer and hits the primer fixed to the base of the bullet. The primer impact against the bullet results in its initiation. This cartridge was adopted for rifles in the Prussian Army – needle guns.
Further development of ball cartridges design aimed at shifting the primer to the bottom (head) of the cartridge. In 1835 the French gunsmith C. Lefaucheux filed a patent for cartridge having a primer at the cartridge case base with the pinfire perpendicular to the cartridge case axis. The cartridges of the Lefaucheux type were mass produced since 1850 and until WWI they were in common use particularly for shotgun and revolver cartridges, but in a form more advanced against the original construction. As a quite curiosity this type of cartridges and newly produced firearms can still be encountered in France even today. Subsequent cartridges had the primer situated to the centre of the cartridge case. The primer had been initiated by the impact of the striker in the longitudinal axis direction of the cartridge through the cartridge case base. Similarly, as is known in today’s cartridges. Though the primers were still positioned at the inside of the cartridge case and for their initiation it was necessary to deform the cartridge case base. These cartridges with so called ´inner primer´had to have a thinner cartridge case base, which had a negative effect on its strength, not allowing re-loading and installation of the primer at the cartridge case base to the inside was a rather complex manufacturing process. The ways were sought to shift the primer to the exterior of the cartridge case so as to make the production more simple and also for the reason of capacity for reloading. In England the year 1864 saw the introduction of the first cartridge having external primer Schneider-Daw, which soon gained further followers.
A relatively perfect design of the cartridge which serves as a base even for today’s cartridges was introduced by the English colonel E. M. Boxer in 1865 and American military ordinance officer H. Berdan in 1868. The prime’s principles created by those two inventors are used up to the present and even bear their names indicating characteristic primer design.
THE MAIN PARTS OF THE RIFLE CARTRIDGE ARE:
- CARTRIDGE CASE
- PROPELLANT (POWDER)
Cartridge for the rifles mostly features a bottleneck shape. The bottleneck shape originated from the initial cylindrical or conical shape with the requirement to create a greater space allocated for powder charge while simultaneously downsizing the caliber. At the same time the conical portion of the cartridge case forms an important element of cartridge abutment in the cartridge chamber when the bolt or breech block is closed. The external shape of cartridge case head is from design reasons for easy extraction (ejection) of spent cartridge cases made with groove (for repeating firearms) or with rim (for break-action firearms). The belted cartridge cases are made for the very heavy calibers where the purpose of the belt is the reinforcement of the cartridge case bottom (head) so as to increase its strength.
The material for the hunting rifles cartridge cases production is mostly brass or sometimes deep-drawing steel. The cartridge head contains at its externals a pocket where the primer is inserted. The primer pocket is connected with the powder compartment through the flash holes through which the flame bursts when the primer is initiated and this is followed by the powder charge ignition. The primers are essentially divided into two groups. These are primers with the anvil as an integral part (Boxer) and with the anvil in the primer as a separate part (Berdan). In the case of using the primer with an external anvil the centre of the primer pocket in the cartridge case forms the anvil and in the pocket periphery are usually two flash holes. For the primers having its own integral anvil the primer makes a single unit. The primer is set into the primer pocket in the cartridge case featuring one flash hole. The primers with the anvil as an integral part are used particularly for the pistols and shotguns ammunition, but they are started to be used also for ammunition designed for centerfire rifles. The primers having an integral anvil (Boxer) allow for an easy replacement of the spent primer and make cartridge reloading more simple.
The propellant charge of today’s cartridges is a smokeless powder. For almost 600 years the only propellant used in the firearms was a black powder. Rapid development of chemistry during 19th century enabled to invent another propellant having significantly higher quality than the black powder used to have which was manufactured from the mixture of charcoal, potassium nitrate and sulphur. At the beginning of 1864 when the Prussian Major E. Schulze invented the first semi-smokeless powder thus opening the way to smokeless powders, the development of which was culminated by mastering the technology of nitrocellulose processing in 1880s. In 1884 a French chemist Vielle introduced a smokeless powder made of gelatinized nitrocellulose, 1889 saw the commencement of production of the Nobel’s powder Ballistite and Abel’s Cordite.
The use of smokeless powders, which have much higher energy, meant a rise in the muzzle velocity and increase in the initial and also in the impact energy of the projectile. This enabled reduction of firearms bores and projectiles diameters to 7 and 8 mm while keeping or even attaining higher impact energy.
The bullet is set-in at the cartridge case lapped and firmly secured with so called crimping, so as to prevent any tendencies for fall out or rotation. The firmness of crimping is very important and determines the bullet pull force needed for the bullet release from the cartridge case. The bullet pull affects among others initial pressure conditions in shot generation, and by this also inner ballistics and often also a resulting quality of fire. The quality ammunition has the bullet and also the primer lacquered over in order to ensure moisture-tightness of the cartridge. The cartridges can be even water-tight when using a special flexible lacquer. For hunting rifle cartridges users the most important part of the cartridge is the bullet. The construction of the bullet and its properties has the most profound effect on the hunting qualities of the bullet and the cartridge as a whole. Therefore it is absolutely essential to examine, before its selection, the type of bullet construction and to choose such ammunition, the bullet of which will be the best suited to the type of the game hunted and to the hunting conditions so as to provide a reliable lethal effects.
Source: Dr. Ing. Jiří Hanák M. Sc.