The ornamental design for a sight for use on firearms, as shown and described.
FIG. 1 is a right rear perspective view of a sight for use on firearms showing my new design; and,
FIG. 2 is a rear perspective view thereof.
The broken lines are for purposes of illustration only and form no part of the claimed design.
The portions of the design provided with surface shading have been shaded to represent that the surface exhibits an area of contrasting appearance relative to any surrounding structures.