The butt stock sling stud on my 1977 Marlin 336 in .35REM is mounted in what looks like the bullseye spot. The front sling post is on a barrel ring. I have searched a lot of pictures on Gunbroker of 336 .35REM Marlins and I see a lot of rifles with the stock sling stud in that position. Did Marlin put the sling mount and NO BULLSEYE on that model rifles? Or is that ring mount on the barrel an ADD-ON and the previous owner put a stud in the BULLSEYE? As you can see there was never a sling mount stud installed on this Marlin....