Ballistic sealing, component retention, and projectile launch control for an ammunition cartridge assembly

An ammunition cartridge assembly, comprising:

• a case having a front end and a base end positioned along a longitudinal axis;
• a projectile positioned along the longitudinal axis towards the front end of the case;
• an endcap coupled to the front end of the case and adapted to retain the projectile at least partially within the case;
• a primer positioned along the longitudinal axis towards the base end of the case;
• a primer support coupled to the base end of the case and adapted to support the primer within the case;
• a first obturating lip seal to seal the endcap to the case;
• a second obturating lip seal to seal the primer support to the case;
• and
• a third obturating lip between the end cap and the projectile.

A telescoped ammunition cartridge assembly, comprising:

• a case having a front end and a base end positioned along a longitudinal axis;
• a projectile positioned along the longitudinal axis towards the front end of the case;
• an endcap coupled to the front end of the case and adapted to retain the projectile entirely within the case, wherein the endcap defines a through-hole having a diameter that is sized to receive and retain the projectile prior to firing and the end cap includes a stepped interface facing towards the through-hole to control shot start force and to increase firing accuracy;
• a primer positioned along the longitudinal axis towards the base end of the case;
• a primer support coupled to the base end of the case and adapted to support the primer within the case;
• and
• at least one obturating lip seal to seal at least one of the endcap or the primer support to the case.

An ammunition cartridge assembly, comprising:

• a case having a front end and a base end positioned along a longitudinal axis;
• a projectile positioned along the longitudinal axis towards the front end of the case;
• an endcap coupled to the front end of the case and adapted to retain the projectile at least partially within the case, wherein the endcap defines a through-hole having a diameter that is sized to receive and retain the projectile prior to firing and the endcap includes a C-shaped portion that is coupled to the projectile, wherein the C-shaped portion is adapted to flex inwards during firing to seal against the projectile body to prevent gas leakage;
• a primer positioned along the longitudinal axis towards the base end of the case;
• a primer support coupled to the base end of the case and adapted to support the primer within the case;
• a first obturating lip seal to seal the endcap to the case;
• and
• a second obturating lip seal to seal the primer support to the case.