Reduced energy training cartridge for self-loading firearms

A reduced energy cartridge for use with a dedicated training firearm or firearm modified to a training configuration, the cartridge comprising:

• a piston sleeve defining a projectile cavity at a longitudinal end, a projectile coupled therein, and a cylindrical cavity at a second end for coupling with a primary case, wherein the sleeve further comprises an inwardly extending wall separating the projectile cavity and the cylindrical cavity at the second end, the inwardly extending wall having a central axial cylindrical bore defining a flash hole connecting the projectile cavity with the second end;
• and the primary case configured as a piston and being coupled with the second end of the piston sleeve, the primary case defining a primary case cavity for coupling with a propellant unit, a propellant unit coupled in the primary case cavity for creating a quantity of propellant gas, the primary case further defining a central axial channel for conveying the quantity of propellant gas from the propellant unit when it is created in the primary case cavity to the flash hole and to the projectile in the projectile cavity, wherein the central axial channel is aligned with the flash hole along a central longitudinal axis such that the quantity of propellant gas when created is conveyed substantially along the central longitudinal axis from the propellant unit, and the piston sleeve and primary case providing a direct open pathway along said central longitudinal axis all of the way between the propellant unit and the projectile, the primary case having an O-ring engaged with the cylindrical cavity, and wherein the inwardly extending wall has a frusto-conical surface adjoining the cylindrical bore defining the flash hole, the frusto-conical surface and flash hole being coaxial along the central longitudinal axis, the frusto-conical surface facing the projectile.

A reduced energy cartridge for use with a dedicated training firearm or firearm modified to a training configuration, the cartridge comprising:

• a piston sleeve defining a projectile cavity at a longitudinal end, a projectile coupled therein, and a cylindrical cavity at the second end for coupling with a primary case, wherein the sleeve further comprises a inwardly extending wall separating the projectile cavity and the cylindrical cavity at the second end, the inwardly extending wall having a central axial cylindrical bore defining a flash hole connecting the projectile cavity with the second end;
• the primary case configured as a piston and being coupled with the second end of the piston sleeve, the primary case defining a primary case cavity for coupling with a propellant unit, a propellant unit coupled in the primary case cavity for creating a quantity of propellant gas, the primary case further defining a central axial channel for conveying the quantity of propellant gas from the propellant unit when it is created in the primary case cavity to the flash hole and to the projectile in the projectile cavity, wherein the central axial channel is aligned with the flash hole along a central longitudinal axis such that the quantity of propellant gas when created is conveyed substantially along the central longitudinal axis from the propellant unit, and the piston sleeve and primary case providing a direct open pathway between the propellant unit and the projectile;
• wherein the inwardly extending wall has a frusto-conical surface adjoining the cylindrical bore defining the flash hole, the frusto-conical surface facing the primary case and in part defining a cavity between the primary case and the inwardly extending wall.

A reduced energy cartridge for use with a dedicated training firearm or firearm modified to a training configuration, the cartridge comprising:

• a piston sleeve defining a projectile cavity at a longitudinal end, a projectile coupled therein, and a cylindrical cavity at the second end for coupling with a primary case, wherein the sleeve further comprises a inwardly extending wall separating the projectile cavity and the cylindrical cavity at the second end, the inwardly extending wall having a central axial cylindrical bore defining a flash hole connecting the projectile cavity with the second end;
• the primary case configured as a piston and being coupled with the second end of the piston sleeve, the primary case defining a primary case cavity for coupling with a propellant unit, a propellant unit coupled in the primary case cavity for creating a quantity of propellant gas, the primary case further defining a central axial channel for conveying the quantity of propellant gas from the propellant unit when it is created in the primary case cavity to the flash hole and to the projectile in the projectile cavity, wherein the central axial channel is aligned with the flash hole along a central longitudinal axis such that the quantity of propellant gas when created is conveyed substantially along the central longitudinal axis from the propellant unit, and the piston sleeve and primary case providing a direct open pathway between the propellant unit and the projectile;
• wherein the inwardly extending wall has a pair of frusto-conical surfaces adjoining the cylindrical bore defining the flash hole, one frusto-conical surface facing the projectile and one facing the primary case.

A reduced energy cartridge for use with a dedicated training firearm or firearm modified to a training configuration, the cartridge comprising:

• a piston sleeve defining a projectile cavity at a longitudinal end, a projectile coupled therein, and a cylindrical cavity at a second end for coupling with a primary case, wherein the sleeve further comprises an inwardly extending wall separating the projectile cavity and the cylindrical cavity at the second end, the inwardly extending wall having a central axial cylindrical bore defining a flash hole connecting the projectile cavity with the second end;
• and the primary case configured as a piston and being coupled with the second end of the piston sleeve, the primary case defining a primary case cavity for coupling with a propellant unit, a propellant unit coupled in the primary case cavity for creating a quantity of propellant gas, the primary case further defining a central axial channel for conveying the quantity of propellant gas from the propellant unit when it is created in the primary case cavity to the flash hole and to the projectile in the projectile cavity, wherein the central axial channel is aligned with the flash hole along a central longitudinal axis such that the quantity of propellant gas when created is conveyed substantially along the central longitudinal axis from the propellant unit, and the piston sleeve and primary case providing a direct open pathway along said central longitudinal axis all of the way between the propellant unit and the projectile, the primary case having an O-ring engaged with the cylindrical cavity, and wherein the flash hole further has a first end and a second end, wherein the first end is proximate to the projectile cavity and comprises a frusto-conical shape, the first end with the frusto-conical shape and the flash hole being coaxial along the central longitudinal axis.

A reduced energy cartridge for use with a dedicated training firearm or firearm modified to a training configuration, the cartridge comprising:

• a piston sleeve defining a projectile cavity at a longitudinal end, a projectile coupled therein, and a cylindrical cavity at a second end for coupling with a primary case, wherein the sleeve further comprises an inwardly extending wall separating the projectile cavity and the cylindrical cavity at the second end, the inwardly extending wall having a central axial cylindrical bore defining a flash hole connecting the projectile cavity with the second end;
• and the primary case configured as a piston and being coupled with the second end of the piston sleeve, the primary case defining a primary case cavity for coupling with a propellant unit, a propellant unit coupled in the primary case cavity for creating a quantity of propellant gas, the primary case further defining a central axial channel for conveying the quantity of propellant gas from the propellant unit when it is created in the primary case cavity to the flash hole and to the projectile in the projectile cavity, wherein the central axial channel is aligned with the flash hole along a central longitudinal axis such that the quantity of propellant gas when created is conveyed substantially along the central longitudinal axis from the propellant unit, and the piston sleeve and primary case providing a direct open pathway along said central longitudinal axis all of the way between the propellant unit and the projectile, the primary case having an O-ring engaged with the cylindrical cavity, wherein the channel has a first end and a second end, wherein channel comprises a constant diameter between the first and second end, and wherein the first and second ends are beveled.