The ornamental design for a gun-shaped flag pole holder, as shown and described.
FIG. 1 is a perspective view of a gun-shaped flag pole holder shown in a position of use supporting a flag pole.
FIG. 2 is a side view of the gun-shaped flag pole holder of FIG. 1.
FIG. 3 is a first end view of the gun-shaped flag pole holder of FIG. 1.
FIG. 4 is a second end view of the gun-shaped flag pole holder of FIG. 1.
FIG. 5 is an overhead view of the gun-shaped flag pole holder of FIG. 1; and,
FIG. 6 is an underside view of the gun-shaped flag pole holder of FIG. 1.
A flag, a flag pole, and a bottom attachment to a flag pole holder, all drawn in broken lines in FIG. 1, are depictions of environmental subject matter that form no part of the claimed design.