Adjusting device (1) for an adjustable rest (2, 2a, 2b) for a rifle stock (3), comprising: a first portion (4) adapted to be fixedly arranged to the rifle stock (3), an adjusting portion (5) adapted to be releasably engaged with the first portion (4) and movable between an engaged, locking position and a disengaged, release position upon actuation of the adjusting portion (5), wherein the adjusting portion (5) is adjustable in relation to the first portion (4) in a release position, and wherein the adjusting portion is locked in relation to the first portion (4) in the locking position, wherein the adjusting portion (5) is adapted to be fixedly arranged to the adjustable rest (2, 2a, 2b).