Bisley SHOTGUN & RIFLE SLING SWIVELS, Barrel & Wood Fit
These Bisley Sling Swivels come in two parts - one with a screw thread that fits into your stock and a second part that clamps around your barrel. Ideal for fitting to guns with no existing swivel posts. My lad uses the 20mm fitting on his semi auto 12g as this fits perfectly onto his barrel and the screw threaded part was easy to tap into his synthetic stock.