The ornamental design for a magazine well extension, as shown and described.
FIG. 1 is a right side view of a magazine well extension in accordance with the present disclosure attached to an unclaimed firearm;
FIG. 2 is an isometric view of the magazine well extension of FIG. 1;
FIG. 3 is a front elevation view of the magazine well extension of FIG. 1;
FIG. 4 is a rear elevation view of the magazine well extension of FIG. 1;
FIG. 5 is a right side elevation view of the magazine well extension of FIG. 1;
FIG. 6 is a left side elevation view of the magazine well extension of FIG. 1; and,
FIG. 7 is a top view of the magazine well extension of FIG. 1.
The broken lines and areas adjacent to the solid lines in the Figures depict portions of the magazine well extension that form no part of the claimed design. The broken lines illustrating the firearm in FIG. 1 are included to show the magazine well extension in an environment of use and form no part of the claimed design.