Abstract: A cartridge case 76 for a cased telescoped ammunition round 10. Cartridge case 76 includes a hollow cylindrical outer casing 12 the axis 18 of which is also the axis of symmetry of round 10. The inner surface of outer casing 12 has a longitudinal groove 50 formed in it along which groove 48 outer casing 12 splits when round 10 is fired. A front seal 20 closes the front end of casing 12 and a rear seal 22 closes the rear end of casing 12. A hollow cylindrical control tube 24 is secured to rear seal 22 so that control tube 24 is symmetric with axis 18. Three bolts 52, 53, 54 which are made of a material having a yield strength greater than the maximum stress to which the bolts 52, 53, 54 are subjected when round 10 is fired interconnect front and rear seals 20, 22.