The ornamental design for a pistolcaliberar-15 upper receiver, as shown and described.
FIG. 1 is a right side view thereof;
FIG. 2 is the left side view thereof;
FIG. 3 is a perspective view showing the top view, front view and left side view thereof;
FIG. 4 is a perspective view showing the top view, front view and right side view thereof;
FIG. 5 is a top side view thereof;
FIG. 6 is a bottom side view thereof;
FIG. 7 is a front side view thereof; and,
FIG. 8 is a rear side view thereof.
Many aspects of the invention can be better understood with reference to the following drawings. For the drawings, the shading indicates a contrast of appearance and does not necessarily describe any color, texture, or material.