Neckless cartridge
View Patent ↗A cartridge with a composite cartridge case includes a projectile with an ogee-shaped tip and a bottom end ending in a base, a flangeless tubular case delimiting a chamber accommodating a propulsive powder, closed at a first longitudinal end by a base with a primer and at the second end opposite to the first, by the base of the projectile, a part of the flangeless tubular case fitting snugly around part of the projectile and having itself, at least in part, a frustoconical external shape, the cartridge being characterized in that: —the chamber accommodating the propulsive powder includes, at the projectile end, a reduction in its diameter over all or part of the periphery thereof down to the diameter of the base of the projectile, —the ratio between the length of the tip of the projectile and the maximum diameter thereof is greater than or equal to 2.9.
1. A cartridge comprising:
a projectile with an ogival-shaped nose and a base ending with a head; and
a polymer neckless tubular case defining a propellant powder receiving chamber closed at a first longitudinal end by a head with a primer and at a second longitudinal end that is opposite to the first longitudinal end by the head of the projectile, with a portion of the neckless tubular case enclosing a portion of the projectile and the portion of the neckless tubular case enclosing a portion of the projectile having, at least in part, a frustoconical external shape,
wherein the propellant powder receiving chamber has, on the projectile side, a reduction of the diameter of the propellant powder receiving chamber over at least part of the periphery of the propellant powder receiving chamber up to the diameter of the head of the projectile,
the ratio between the length of the nose of the projectile and the maximum diameter of the projectile is greater than or equal to 2.9,
the projectile has a base having, at least in part, a gradual reduction of the diameter of the base up to the head of the base, and
the case has, at the second longitudinal end of the case and in the head-projectile direction, a first portion having, over at least part of the perimeter of the first portion, a gradual reduction of the internal diameter of the first portion up to the head of the projectile, a second portion of an external diameter equal to the diameter of the first portion and of an increasing internal diameter conforming to a portion of the base of the projectile and then a terminal portion constituted by a shoulder, an inner face of the shoulder being in contact with the projectile.
2. The cartridge according to claim 1 , wherein the ratio between the length of the nose of the projectile and the diameter of the projectile is between 2.9 and 4.1.
3. The cartridge according to claim 1 , wherein the reduction of the diameter of the combustion chamber up to the diameter of the head of the projectile corresponds to a gradual reduction of the internal diameter of the case, the case having, at this level, a frustoconical shape with a half-angle α between 20 and 40 degrees.
4. The cartridge according to claim 1 , wherein the length of the second portion is at least equal to a third of the length of the terminal portion.
5. The cartridge according to claim 1 , wherein the caliber of the cartridge is 5.56 mm.
6. The cartridge according to claim 5 , wherein the caliber of the cartridge is 5.56 mm and the maximum length of the cartridge is 57.4 mm (2.26 in).
7. The cartridge according to claim 1 , wherein the ratio between the length of the nose of the projectile and the diameter of the projectile is about 3.5.
8. The cartridge according to claim 1 , wherein the caliber of the cartridge is 7.62 mm.
9. The cartridge according to claim 1 , wherein the caliber of the cartridge is 12.7 mm.
10. The cartridge according to claim 8 , wherein the caliber of the cartridge is 7.62 mm and the maximum length of the cartridge is 71.9 mm (2.83 in).
11. The cartridge according to claim 9 , wherein the caliber of the cartridge is 12.7 mm and the maximum length of the cartridge is 140.8 mm (5.545 in).