The ornamental design for a gunfile, as shown and described.
FIG. 1 is a perspective view of a gun file.
FIG. 2 is a front view of a gun file.
FIG. 3 is a rear view of a gun file.
FIG. 4 is a top view of the view of a gun file.
FIG. 5 is a bottom view of a gun file.
FIG. 6 is a side elevational view of a gun file, the opposite side being a mirror image thereof;
FIG. 7 is a front perspective view of an inside of a gun file; in this view the broken lines are for illustrative purposes only and form no part of the claimed design; and,
FIG. 8 is a front elevational view of a gun file shown in the context of a shelf in a gun safe; in this view the broken lines are for illustrative purposes only and form no part of the claimed design.