A unitary cartridge is an artillery shot with one feature: in it, the sleeve combines a component for ignition (primer), a charge of the gunpowder itself and a bullet. There is a second definition of such a cartridge - this is the ammunition of small-caliber guns (less than 7.6 cm) and small-arms weapons. It charges in one go.
History
The unitary cartridge got its name in the 19th century. It was distinguished from previous versions of cartridges by the combination in the sleeve of all the important components for the implementation of the shot.
The designated cartridges originated in the first half of the 19th century. The first unitary cartridges were presented by the famous German master Nikolai Dreyse in 1827. But his models did not make the proper impression.
In 1853, his colleague from France, Casimir Lefoshe, invented a cartridge model with a pin and a metal sleeve. Its device is such that the end of the stud, placed in front of the percussion kit of the primer, came out through a hole in the side of the sleeve. And when the drum turned, the primer took the attack of the trigger.
Unitary cartridge allowed severalincrease the rate of fire. But an important event for the development of this characteristic occurred in 1818. Then the English master Joseph Ett created a primer.
This is a cap made of copper, which is placed in an incendiary mixture. He was strung apart on a brand pipe. And during the shot, it was destroyed by a hammer blow. Paper caps were also used.
Draize and Lefoche
Dreyse was invented in 1827. The designer had the following manufacturing scheme:
- Paper shell filled with gunpowder.
- A solid cylinder was inserted into it. At its base, a percussion mechanism was imprinted from below. A recess was made in the upper base, which corresponded in shape to the bullet.
In 1853, Lefoshe improved the model - he replaced the paper sleeve with a metal one. And such a unitary cartridge consists of:
- bullets;
- gunpowder charge;
- shells;
- capsules.
In the analysis, a picture is obtained, as shown in the photo.
When the trigger was pulled down, a special needle pierced the charge and the seal of the shock group. There was an ignition of the seal, and then a shot followed. At this moment, a cylinder filled with powder gases entered the rifled components of the barrel, compressing the bullet. And she was spinning along the rifling.
A unitary cartridge having a metal sleeve was created with two main objectives:
- Greatly increase the dynamics of the rate of fire.
- Block powder gases during the shot.
This sleeve increased and adjoined the walls of the store and the front shear of the shutter. So the gases could no longer escape through the shutter. And after the shot, the sleeve took the original parameters. Therefore, it could be easily removed from the barrel.
According to these principles, the cartridges of the Lefoshe version are divided into two classifications.
Classifications of metal unitary cartridges
There are only two of them:
- Models with seamless sleeves.
- Composite models.
In seamless cartridge cases of unitary cartridges, the bottom and walls on the sides are a single whole. To create it, sheet brass with alternate hoods is used.
The compound versions use a thin sheet of brass. It folds in at least 1-2 turns. The separate bottom is firmly fastened to the walls on the sides.
During the shot, the cartridge case expands. Its extreme sides tightly touch the chamber. It is easy to remove the sleeve after the shot, even if the gap is significant.
Seamless variations work without failures only with a modest gap - a maximum of half a point.
When the sleeve gets its proper shape, its inner walls are varnished. So the metal is protected from oxidation. After that, a capsule is placed in the bottom.
Categories of cartridges by position of the strike complex
Unitary cartridges according to this criterion are distributed into the following groups:
- With rimfire. The shock complex is compressed inside the sleeve along the entire diameter of its bottom.
- Scentral fire. The complex is locked in a capsule and placed in the middle of the bottom.
All compound versions of cartridges belong to the second group. In the first group, they would simply burst and excessive gas pressure.
Famous models from the first category are:
- 4, 2-line model for Berdan rifle;
- 6-line version for Krnk rifles.
The Boxer model has gained immense popularity among the composite modifications.
Revolver Lefoshe
When the unitary cartridge appeared, its use in revolvers was not envisaged. The main purpose was long-barreled weapons. But since the rate of fire of revolvers needed to be developed, the adaptation of unitary models for them is associated with the appearance of a metal sleeve.
And here the gunsmith from France Casemir Lefoshe excelled. First, he developed a unitary cartridge suitable for revolvers, and then the most optimal weapon for them. And the first revolver for a unitary cartridge looked like in the photo.
When the trigger is pulled, the hammer hits the top end of the stud. She directs the impulse to the capsule. It explodes. Gunpowder ignites. The resulting gases force the bullet out of the case. Thanks to them, the bullet accelerates strongly, passing its way.
Another feature of the Lefoshe revolver is associated with the introduction of double-effect trigger technology. This allowed the weapon to be fired after manually pulling the trigger and simply pulling the trigger.
Gradually, a revolver with such a system had to be abandoned for the following reasons:
- The case pin was always on alert. She was often accidentally hit, and the weapon fired spontaneously.
- In rare cases, gunpowder fumes hit the shooter's face.
- The sleeves expanded greatly. They were difficult to extract.
Further evolution of revolvers for unitary cartridges
After hairpin technology, revolvers needed to be upgraded. And in 1878 the Belgian master Emil Nagant managed to do this.
He created a revolver that works with unitary models. They used black powder. At the bottom of the sleeve there was a primer. It collapsed with a strike.
In subsequent years, weapons were upgraded many times. The following is a list of upgrades and model examples:
- 1886 Chambered version. The type of gunpowder in them is smokeless. Caliber - 7.5 mm. This is a simpler and more reliable model with improved accuracy of fire.
- 1892 Gas breakthrough blocking model. The type of gunpowder is the same. During the shot, the drum chamber went to the barrel. And thanks to the cartridge, the obturation increased.
- 1895 Modification in which many design ideas were realized. Its author is Leon Nagant, Emil's brother and like-minded person.
Features of the 1895 model
The 1895 revolver had the following features:
- One-piece frame.
- Self-cockingmechanism.
- Seven shot drum.
- Reinforced obturation.
- Cramrod. It passed through the middle of the axis of the drum. With its help, they cleaned weapons and removed cartridge cases.
The cases were removed as follows:
- The ramrod was placed in a holder fixed by hinges on the barrel.
- It was taken out of the drum axis, rotated on the holder. He hit the place opposite the drum chamber.
- After the stages down, the door opened. She blocked the right side of the rear drum end. What caused the opening of the shell bottom.
- The ramrod pressed on the butt. And with its tip it was possible to expel the sleeve or the entire cartridge.
You can load weapons only according to the "one charge - one cartridge" scheme. There is a camera available for this task. You can see it when the drum cover is opened.
This model was appreciated all over the world, including Russia. Many noted her virtues:
- No failures.
- Dust resistant.
- High accuracy and combat power.
Safety measures for self-equipment
If you want to load a unitary cartridge yourself, you must follow the safety criteria:
- Checking the sleeves for cracks. They should not have any cracks. The sleeve is inspected completely and through a magnifying glass. If at its base there are noticeable rings measuring 1-1.5 cm, then it is divided.
- Too much lube. Because of this, dents can occur in the sleeves. Excess lubricant is in the matrix. This threatens to increase the pressure in the sleeve. And it may crack or come off.
- If you load cartridges with a single-action press, store the loaded cases separately from the empty ones. When working with a progressive press, it is better to use a separate apparatus for determining the powder charge.
- If using different types of gunpowder, isolate them from each other.
- The primer must be fully seated. The place of installation of the capsule must be cleaned of soot. Also, the capsule must be placed at the correct depth. This is 0.02 mm deeper than the main surface of the sleeve. Progressive scales will help you keep track of the capsule position.
- Do not deepen the primer too deep. When landing, the capsule should not be deformed.
- Properly trim cases based on chambering.
- Place the bullet at the correct depth. Incomplete bullet seating is usually a common occurrence in sport shooting. For hunting, this practice is not applicable.
- The neck of the sleeve must not be over-compressed. It is optimal to place and compress the bullet at various stations. A simple crimp will do. Do not deform the case neck.
- The neck of the sleeve should not be crimped weakly. If the bullet has a weak fixation, it can fall into the case. Crimping bullets is required with the right amount of force.
- Do not use sleeves with an extended base. They have already used up their cycle.
If these criteria are not met, a danger arises when self-loading unitary cartridges. Most often there are inaccurate shots, jammingbullets and other damage to weapons. There is a risk of being left on the hunt without a trophy. And in the worst case, there is a high risk of injury.
