Hello folks I've come to you with a weird set of sling swivels I've found in the back of the misc. drawer. Looking to put them on a 1998 Ruger 10/22 but I need swivel studs narrow enough to fit them. Point of this topic is that I'm trying to use them so they get out of the drawer before buying a new pair (not about the money) and my questions are as follows: What brand are they and are they worth the trouble (obviously no markings, but made of metal)? If so what kind of studs would they even fit? The opening for the spring loaded quick detach is 4.9mm or 0.19 Inches so I would need a stud slightly smaller than that for them to fit onto. Here's hoping someone doesn't peg them right away as cheapo BB gun swivels, but nevertheless thank you all for your time.