A holder for supporting a long-barreled gun in a vehicle comprises a base and a holder, whereby the base may be removably coupled to the cup holder of a vehicle and the holder is adapted to support the stock of a long-barreled gun. The holder may be adjustable so as to snugly receive various sizes of gun stocks and may be covered in a cushioning material. The height of the holder relative to the base may be adjustable. The base may include one or more cavities adapted for holding bullets. The holder may include a selectively releasable retainer for retaining the stock of the gun in the holder. A method and kit for mechanically coupling two or more gun holding devices so as to prevent movement of one gun holding device relative to the other gun holding devices is also provided.