The ornamental design for a snaphookinterface for a firearm, as shown and described.
FIG. 1 is a front, top, left perspective view of the snap hook interface for a firearm of the present invention shown on a firearm stock at a reduced scale;
FIG. 2 is a is a front, top, left perspective view of the snap hook interface for a firearm of FIG. 1;
FIG. 3 is a left side elevation view of the snap hook interface for a firearm of FIG. 1, the right side being a mirror image thereof;
FIG. 4 is a bottom plan view of the snap hook interface for a firearm of FIG. 1;
FIG. 5 is top plan view of the snap hook interface for a firearm of FIG. 1;
FIG. 6 is a front elevation view of the snap hook interface for a firearm of FIG. 1; and,
FIG. 7 is a rear elevation view of the snap hook interface for a firearm of FIG. 1.
The broken lines showing portions of the design in all figures are included for the purpose of illustrating environment and unclaimed features and form no part of the claimed design. The alternating long and short segment broken line in FIG. 4 is a boundary line showing the bounds of the claimed design.