The ornamental design for a dispensergun, as shown and described.
FIG. 1 is a top left perspective view of the dispenser gun;
FIG. 2 is a left elevation view of the dispenser gun;
FIG. 3 is a right elevation view of the dispenser gun;
FIG. 4 is a bottom plan view of the dispenser gun;
FIG. 5 is a top plan view of the dispenser gun;
FIG. 6 is a front elevation view of the dispenser gun; and,
FIG. 7 is a rear elevation view of the dispenser gun.
Shade lines shown in the accompanying drawings of FIGS. 1-7 represent surface contour only and not texture, color shading, or surface ornamentation. The broken lines depict portions of the dispensing gun in which the design is embodied that are not considered part of the claimed design.