The GunJack provides elevation adjustment for the rear of the gun without carrying around another bag. Its simple rotational cam design allows for infinite adjustment and solid ground contact like a monopod, but adjustments can be made immediately like a bag. To operate it, the shooter uses their off hand to simply squeeze the sides together, to lock the cams to the stock when adjusted as desired. Surface friction from the cams and the sides of the stock provide a surprisingly solid lock with very little squeeze pressure. Patent Pending.