Polymer cartridge with enhanced snapfit metal insert and thickness ratios

A high strength polymer-based cartridge, comprising:

• a polymer case, comprising:
• a first end having a mouth;
• a neck extending away from the mouth and comprising a neck thickness (Tn);
• a shoulder extending below the neck and away from the first end;
• a body formed below the shoulder and having a case thickness (Tc), comprising:
• a flat portion comprising a pull thickness (Tp);
• and
• a dip, closer to the shoulder than the flat portion and comprising a dip thickness (Tb);
• an insert attached to the polymer case opposite the shoulder, comprising:
• a flat section contacting the flat portion and comprising an insert wall thickness (Ti);
• and
• a bulge engaging the dip to maintain the insert on the polymer case;
• and
• a projectile disposed in the mouth having a particular caliber;
• wherein the neck thickness (Tn) and the dip thickness (Tb) are related by a ratio of 1.0≤Tb/Tn<1.5.

A high strength polymer-based cartridge, comprising:

• a polymer case, comprising:
• a first end having a mouth;
• a neck extending away from the mouth and comprising a neck thickness (Tn);
• a shoulder extending below the neck and away from the first end;
• a body formed below the shoulder and having a case thickness (Tc), comprising:
• a base interface portion having a minimum thickness;
• a flat portion comprising a pull thickness (Tp);
• and
• a dip, closer to the shoulder than the flat portion and comprising a dip thickness (Tb);
• an insert attached to the polymer case opposite the shoulder, comprising:
• a flat section contacting the flat portion and comprising an insert wall thickness (Ti);
• and
• a bulge engaging the dip to maintain the insert on the polymer case;
• and
• a projectile disposed in the mouth having a particular caliber;
• wherein the ratio of the minimum thickness of the base interface portion to the neck thickness is between about 1.0 and about 1.5.