The ornamental design for a swivel mount slingadapter, as shown and described.
FIG. 1 is a perspective view of a swivel mount sling adapter shown in a use configuration with environment, showing my new design;
FIG. 2 is an enlarged perspective view thereof;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a rear elevational view thereof;
FIG. 5 is a left-side elevational view thereof;
FIG. 6 is a right-side elevational view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The evenly spaced broken lines in FIG. 1 depict environment of a firearm and a sling that forms no part of the claimed design. The evenly spaced broken lines in FIGS. 1, 2, and 3 depict portions of the swivel mount sling adapter that form no part of the claimed design. The dot-dash-dot broken lines in FIG. 1 depict the boundaries of the environment that form no part of the claimed design.