CZ27244U1 - Barrel for hand-held firearms of Flobert gun type with reduced kinetic energy of the projectile, at the most 7.5 J - Google Patents

Description

Barrel for small arms flobert type with reduced kinetic energy missiles, most

7,5 J

Technical field

Small arms with administrative limited kinetic missiles, maximum 7.5 J. Flobertky category D.

BACKGROUND OF THE INVENTION

In addition to the sliding movement along the flight path missiles perform rotationally stabilized missiles very complex intrinsic movement around their center of gravity. Its most important component is rotation about the longitudinal axis. Thanks to it the bullet behaves like a flywheel - the force adaptation does not deviate in the direction of the applied force, but perpendicular to it.

In the case of stable missile flight, the stabilization condition must be observed that the gyroscopic stability number must be greater than 1. In the calculation formula of this inequality, with otherwise constant properties of projectile design, environmental resistance, angle of attack, this condition is affected only by angular velocity second, the rotary movement of the missile.

Missiles 22 Flobert CB, fired from the barrel of dimensions according to the standard C.I.P. for this charge, but used for a weapon with a reduced muzzle energy to a legal value of not more than 7.5 J, have a gyroscopic stability number of less than 1, resulting in an unstable scattering distance of 10 to 15 m. By an approximate calculation, a gyro stability number of about 0.8 was found under these conditions under the above conditions. It is clear that the bore pitch according to C.I.P. suitable for a full-energy missile 39 J with a muzzle velocity of 260 m / s, not suitable for a missile with a limited energy of 7.5 J with a muzzle velocity of about 114 m / s and that this disadvantage is due to the lower angular velocity given borehole in conjunction with muzzle velocity.

Another disadvantage is mainly in the cross-section of the C.I.P. is that the diameters of the bullets of the Flobert CB hubs 22 are made within tolerances limiting only the upper dimension. When a shot-bore pair interacts with a shot, it may happen that the bullet is poorly guided by the bore and “beats”. The result is also increased scattering.

The essence of the technical solution

These drawbacks are largely eliminated by the grooved bore barrel of the present invention, used for firearms of the Flobert type with a limited kinetic energy of the missile to a maximum of 7.5 J and for firing 22 Flobert CB cartridges, the advantage of which is to increase angular velocity of the projectile and eliminates the effect of production tolerances projectile missile guidance in the grooved guiding part of the bore, whose essence is that the barrel bore is made in the grooved guiding part of field diameter F * = 5.48 mm nominal size, groove diameter Z = 5.65 mm of nominal size and groove pitch u = 240 mm of nominal size, the number of grooves N being at least 4 and the tolerance field for dimension F * is +0.02 mm, for dimension Z is -0.02 / + 0.03 mm and for dimension u is -80 / + 120 mm.

Example of technical solution

A cylindrical barrel with a bore of the guiding portion with a field diameter of 5.49 mm, a groove diameter of 5.65 mm, a groove pitch of 270 mm and a number of grooves 12 were used in a one-shot long flobert modified to 6.8 J muzzle energy. speed of 103.2 m / s projectile shells 22 Flobert CB. When shooting at a distance of 10 m was achieved significantly better dispersion than with a gun with a barrel size according to C.I.P. and the gyroscopic stability number was calculated to be 1.2.

Claims (2)

PROTECTION REQUIREMENTS 1. Flobert type 22 Flobert CB handgun barrel with limited missile kinetic energy up to 7.5 J when firing 22 Flobert CB cartridges, characterized in that the grooved bore guide portion is made in nominal field diameter dimensions 5 F * = 5.48 mm, groove diameter Z = 5.65 mm, pitch u = 240 mm and number of grooves N at least 4. Barrel according to claim 1, characterized in that the tolerance field for the dimension F * is + 0.02 mm, for the dimension Z is -0.02 / + 0.03 and for the dimension u is -80 / + 120 mm.