I claim the ornamental design of a rifle foregrip, as shown and described.
FIG. 1 is a left side view of a rifle foregrip showing my design;
FIG. 2 is a right side view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a top view thereof;
FIG. 6 is a bottom view thereof;
FIG. 7 is a rear perspective view thereof; and,
FIG. 8 is a front perspective view thereof.
The broken lines in the drawings represents ancillary features of the rifle grip, which are illustrated only for the purpose of understanding the design, and form no part of the claimed design.