The ornamental design for spray gun cartridge, as shown and described.
FIG. 1 is a bottom view of a spray gun cartridge;
FIG. 2 is a right perspective view of the spray gun cartridge of FIG. 1, with the left perspective view being a mirror image of the right perspective view;
FIG. 3 is a right side view of the spray gun cartridge of FIG. 1, with the left side view being a mirror image of the right side view;
FIG. 4 is a front side view of the spray gun cartridge of FIG. 1, with the rear side view being a mirror image of the front side view;
FIG. 5 is an top view of the spray gun cartridge of FIG. 1;
FIG. 6 is a front side exploded view of the spray gun cartridge of FIG. 1, with the rear side exploded view being a mirror image of the front side exploded view; and,
FIG. 7 is a right side exploded perspective view of the spray gun cartridge of FIG. 1, with the left side exploded perspective view being a mirror image of the right side exploded perspective view.
The purpose of broken lines in the drawings is to show the spacial relationship between the spray gun cartridge and the inner vase. The portion of the drawings shown in broken lines forms no part of the design to be patented.