The ornamental design for a magazinecoupler, as shown and described.
FIG. 1 is a top right side perspective view the magazine coupler coupled to a pair of magazines shown in broken lines and showing the ammunition carrier cover removed to show the interior of the ammunition carrier;
FIG. 2. Is a rear elevation view thereof;
FIG. 3 is a right side view thereof;
FIG. 4 is a top right side perspective view showing the ammunition carrier cover in place;
FIG. 5 is an exploded view top right perspective view showing the ammunition carrier cover removed to show the interior of the ammunition carrier;
FIG. 6 is a rear elevation view thereof;
FIG. 7 is a front elevation view thereof;
FIG. 8 is a right side elevation view thereof;
FIG. 9 is a left elevation view thereof;
FIG. 10 is a top plan view thereof; and,
FIG. 11 is bottom plan view thereof.
The broken lines showing of two coupled magazines in FIGS. 1 through 3 represent environment which do not form a part of the claimed design. The broken lines showing of portions of the magazine coupler in FIGS. 1 through 11 do not form a part of the claimed design.