The ornamental design for a gunsightadjustmentdevice, as shown and described.
FIG. 1 is a front perspective view of the design of this invention;
FIG. 2 is a back perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a back view thereof;
FIG. 5 is a first side view thereof;
FIG. 6 is a second side view thereof;
FIG. 7 is a top end view thereof; and,
FIG. 8 is a bottom end view thereof.
The broken line showing of portions of the gun sight adjustment device is included for the purpose of illustrating environment and forms no part of the claimed design.