I claim the ornamental design for a riflescope, as shown and described.
FIG. 1 is an isometric view of a riflescope in accordance with an embodiment of the invention;
FIG. 2 is a left side elevation of the riflescope of FIG. 1, of which the right side elevation (not shown) is a mirror image;
FIG. 3 is an objective end elevation of the riflescope of FIG. 1;
FIG. 4 is a top plan view of the riflescope of FIG. 1; and,
FIG. 5 is a bottom plan view of the riflescope of FIG. 1.
The broken line showing of parts of the drawings is included for the purpose of illustrating use and environment and forms no part of the claimed design.