Projectile of a guided ammunition with bearing unit, wherein the projectile contains a first projectile part and a second projectile part along a longitudinal axis, the two projectile parts (8a,b) being connected with the aid of the bearing unit and being displaceable in respect of one another in the axial direction between a barrel position and a flight position, both projectile parts (8a,b) abutting one another in axial direction in the barrel position and being spaced apart from one another in the flight position, both projectile parts (8a,b) being rotatable in relation to one another about the longitudinal axis in the flight position with the aid of the bearing unit, - having a roller bearing with a first and a second ring (20a,b) and rolling elements, - having a first mounting portion of the first projectile part and a second mounting portion of the second projectile part, - wherein the first ring is fixed on the first mounting portion in the axial direction and the second ring is mounted on the second mounting portion such that it is displaceable in the axial direction, - having a spring element which, in the barrel position, prestresses the second ring in the axial direction in a firing direction of the projectile in respect of the second projectile part with a prestressing force, - the spring element being set up to transfer the projectile from the barrel position into the flight position after it has been fired, - the spring assembly containing a first and a second assembly part in the axial direction, the first assembly part facing the second ring and the second assembly part facing the second mounting portion, and both assembly parts (48a,b) being uncoupled in the barrel position by a support element resting against a stop counter to the firing direction and the assembly parts (48a,b) are coupled in the flight position by the support element which is lifted off the stop and is movable in the axial direction. - having a roller bearing with a first and a second ring (20a,b) and rolling elements, - having a first mounting portion of the first projectile part and a second mounting portion of the second projectile part, - wherein the first ring is fixed on the first mounting portion in the axial direction and the second ring is mounted on the second mounting portion such that it is displaceable in the axial direction, - having a spring element which, in the barrel position, prestresses the second ring in the axial direction in a firing direction of the projectile in respect of the second projectile part with a prestressing force, - the spring element being set up to transfer the projectile from the barrel position into the flight position after it has been fired, - the spring assembly containing a first and a second assembly part in the axial direction, the first assembly part facing the second ring and the second assembly part facing the second mounting portion, and both assembly parts (48a,b) being uncoupled in the barrel position by a support element resting against a stop counter to the firing direction and the assembly parts (48a,b) are coupled in the flight position by the support element which is lifted off the stop and is movable in the axial direction.