I claim the ornamental design for a box turkey call, as shown and described.
FIG. 1 is a perspective view of a box turkey call showing my new design;
FIG. 2 is a back elevation thereof;
FIG. 3 is a front elevation view thereof;
FIG. 4 is a right-side elevation view thereof;
FIG. 5 is a left-side elevation view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken lines showing portions of the paddle and box are included for the purpose of illustrating environmental structure and form no part of the claimed design.