RU2318175C2 - Cartridge of small arms for underwater firing - Google Patents

Abstract

FIELD: small arms ammunition, applicable in construction of a special underwater cartridge for universal two-medium (underwater-surface) weapon as well as for a special underwater weapon.

SUBSTANCE: the main geometric and structural parameters of the nose, cylindrical parts and of the entire bullet satisfy the following relations:

where d(x)-the diameter of the nose part contour at distance x from cavitator plane

- the cavitator diameter, d-the bullet caliber equal to the weapon barrel caliber,

- the length of the nose part;

- the length of the cylindrical leading part,

- removal of the bullet mass center from the cavitator plane.

EFFECT: provided production of a universal two-medium weapon used at firing in water and in the air.

2 dwg

Description

The invention relates to ammunition for small arms and can be used in the construction of a special underwater cartridge for a universal two-medium (underwater surface) weapon, as well as for a special underwater weapon.

The armament of a modern combat swimmer uses a small-arms firearm with a cartridge, in which a powder charge ejects a uniform smooth pointed arrow-bullet. This form has, for example, a bullet according to the US patent [1]. It has a truncated cone-shaped head, a cylindrical body and a feathered tail.

The disadvantage of this underwater bullet-arrow is that it has a large length, which in turn leads to a large cartridge length and requires special underwater weapons.

Known adopted for the prototype 5.66 mm cartridge for underwater firing of the MPS for a special underwater smooth-bore automatic submachine gun APS [2]. The cartridge is built according to the classical structural scheme with the use of a large elongation bullet in the form of a monolithic steel core with a length of over 20 calibers with a conical head and a flat cavitator. With such a large elongation of the bullet, its steady movement under water is simply ensured in the developed cavitation flow regime due to gliding of the stern along the inner surface of the cavity. However, due to the large elongation of the bullet, the relative length of the cartridge increases to 26.5 calibres. In contrast to the MPS cartridge, standard land-based 5.45 × 39 mm and 7.62 × 39 mm machine gun cartridges are 2.6 times shorter. Therefore, the cartridge type MPS cannot be used for a universal two-medium machine with a single magazine design for land and underwater cartridges when firing on land and under water. The cartridge type MPS can only be used for special underwater weapons. However, the large length of the cartridge increases the dimensions of the store, the length of the receiver, the dimensions of the weapon and, therefore, impairs the maneuverability of the weapon.

Thus, the disadvantage of the prototype, as well as the analogue, is the large length of this underwater machine gun cartridge, exceeding the length of 5.45 × 39 mm and 7.62 × 39 mm land machine gun cartridges by 2.6 times.

The invention eliminates this drawback and solves the problem of creating for a universal two-medium weapon a special underwater cartridge, the length of which is equal to the length of a standard land cartridge used in a two-medium weapon when firing in the air.

To solve the problem in a cartridge for small arms for underwater shooting, containing a bottle sleeve equipped with an igniter capsule, a propelling charge, a bullet fixed in the sleeve, consisting of a warhead with a flat cavitator leading cylindrical and stern parts, new is that according to the invention , the cartridge has a length equal to the length of the standard land cartridge. The bullet is installed in the sleeve with its emphasis in the conical recess of the bottom of the sleeve with a pointed aft part with a blunt solid angle and fixed by squeezing the sleeve of the sleeve of the conical surface of the head to achieve the maximum possible elongation of the bullet with a limited cartridge length and to prevent the bullet from blocking the seed holes in the bottom of the sleeve. The cylindrical part of the bullet is equipped with two leading belts located at the beginning and end of the cylindrical part and fixed in the annular grooves of the bullet body, or leading protrusions on the body, cutting into the grooves of the barrel channel and providing obturation of the powder gases, message of the angular velocity bullet of its own rotation to improve its near-round stability and accuracy of fire.

The bullet head is made expanding from the cavitator with a step-conical or curvilinear contour shape with dimensions determined from the condition of inscribing the head into the cavity of the cavity with a guaranteed gap. The propellant charge is placed in the annular cavity between the bullet body and the walls of the bottle sleeve, which forms the charging chamber. In this case, the main geometric and structural parameters of the head and cylindrical parts and the entire bullet are selected satisfying the following relationships:

l _cm ≤0.90 l _g ;

where d (x) is the diameter of the contour of the head at a distance x from the plane of the cavitator (0 <x <l _g );

d ₀ is the diameter of the cavitator;

d is the caliber of the bullet equal to the caliber of the barrel of the weapon;

l _g - the length of the head part;

l _C - the length of the cylindrical leading part;

l _cm - the removal of the center of mass of the bullet from the plane of the cavitator.

The indicated ratios were established by calculation and theoretical methods, and then confirmed by experiments, from the conditions for ensuring organized stable movement of the bullet when firing under water in the developed cavitation flow regime with cavitation numbers in the range 0.001 ... 0.060, typical of external ballistics of small arms submarine bullets at ranges firing up to 30 m and immersion depths up to 20 m, as well as from the condition of ensuring minimum initial disturbances when the bullet exits the barrel. The criterion for the stable movement of the bullet in the cavitation flow mode is the condition that there are no touching the borders of the cavity by the parts of the bullet located in front of the center of mass when the bullet rotates until its aft comes into contact with the boundary of the cavity, which is uniquely determined by the diameter of the cavitator and the number of cavitation. Failure to comply with these ratios violates the steady movement of the bullet in the initial portion of the trajectory when firing under water.

The design of the cartridge is illustrated by drawings,

where in Fig.1 shows a General view of the bullet with the designation of the determining parameters included in the above quantitative ratio;

figure 2 is a General view of the cartridge.

The proposed cartridge contains a bottle sleeve equipped with an igniter capsule 1. A bullet 2 is installed in it with an emphasis in the conical recess 3 of the bottom of the sleeve with a pointed aft part 4 with a blunt solid angle and is fixed by squeezing the barrel of the sleeve of the surface of the head part 5. The head of the bullet is equipped with a flat cavitator 6 and has a step-conical or curved shape of the contour. The cylindrical part of the bullet 7 is equipped with two leading belts or leading protrusions 8. The propelling charge 9 is placed in the annular cavity between the bullet body and the walls of the sleeve. In the bottom of the sleeve made seed holes 10.

When initiating the igniter capsule through the seed holes 10 in the bottom of the sleeve, a propellant is ignited and a shot occurs.

The company produced prototype cartridges according to the invention in a 5.45 mm caliber with a cartridge length equal to the length of a regular 5.45 mm automatic 7H6 cartridge, and tested with a positive result.

Information sources

1. US patent No. 3915092, IPC F41B 11/00; prior. 1975.

2. Catalog "Arms of Russia 2001-2002" M., ed. "Military Parade", 2001, p. 691, "5.66 mm cartridge for underwater shooting" - prototype.

Claims (1)

A cartridge for small arms for underwater shooting, comprising a bottle sleeve with an igniter capsule, a bullet fixed in the sleeve, consisting of a head part with a flat cavitator, a cylindrical leading part and a conical stern part, and a propelling charge, characterized in that the cartridge is made in length equal to the length a regular land cartridge, and the aft part of the bullet is made with a blunt solid angle and is installed in the bottom of the sleeve with an emphasis in its conical recess, while the bullet is fixed by compressing the surface of its head part of the muzzle sleeve, the cylindrical part of the bullet is equipped with two leading belts fixed in the annular grooves of the body, made at the beginning and end of the cylindrical part of the bullet, or leading protrusions mounted on the body, cutting into the cuts of the barrel of the gun barrel, the head part of the bullet is expanded from the cavitator stepwise -conic or curved shape of the contour, and a propellant charge placed in the annular cavity between the bullet body and the walls of the sleeve, while the parameters of the bullet are made satisfying the following relations:

l _cm ≤0.90 l _g ;

where d (x) is the diameter of the contour of the head at a distance x from the plane of the cavitator (0 <x <l _g ); d ₀ is the diameter of the cavitator; d is the caliber of the bullet equal to the caliber of the barrel of the weapon; l _g - the length of the head part; l _C - the length of the cylindrical leading part; l _cm - the removal of the center of mass of the bullet from the plane of the cavitator.

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