A packoff and a locking assembly installed in a bore of a wellhead component are provided. In one embodiment, a packoff includes inner and outer annular seals and an energizing ring shaped to be wedged between the inner and outer annular seals so as to apply a radially inward biasing force on the inner annular seal and a radially outward biasing force on the outer annular seal. In another embodiment, a locking assembly includes a lock ring that extends into a recess in a wall of the bore of the wellhead component and an actuator radially disposed between an inner component within the bore and the lock ring to retain the lock ring within the recess. The actuator can have an interference fit with the inner component to inhibit movement of the actuator between the lock ring and the inner component. Additional systems, devices, and methods are also disclosed.