The ornamental design for a projectilelaunchingdevice, as shown and described.
FIG. 1 is a left side perspective view of a projectile launching device showing the new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom thereof; and,
FIG. 8 is a perspective view of the projectile launching device in the context in which it is intended to be used, the dashed line structure being provided for purposes of environment and forming no part of the claimed design.