Trapper bullseye kits

Just found an old Trapper spring kit for D frames still sealed in package. Comes with v spring and bolt spring. Installed the mainspring to lighten pull on my Cobra but left the original bolt spring to prevent possible throw by. DA pull improved to my satisfaction but have not shot it yet.(shoots a pencil across room in SA firing).Anyone used the Trapper bullseye kits in their D frames before.