text: how do i install swivels on my 30 30 marlin rifle? i'm looking towards putting a sling on my 30 30 marlin rifle. i see a pic of them on a website. it appears one swivel mounts on the mag tube and the other on the stock. the rear looks like it has coarse threads on it? on my stock it has what looks like a plastic plug maybe? my question is do i predrill this spot and thread the swivel in there? thanks! bound's hubby here:  kahr t9 is very much on target. the plastic plug you see is marlin's trademark "bullseye".   you can actually puchase a sling swivel kit manufactured by uncle mike's of oregon (see link). the forward swivel mount actually clamps onto the magazine tube, no drilling required!   when you drill the stock for the coarse screw, be careful! make sure the stock is braced, and preferrably using a drill press with a bit slightly smaller than the coarse thread screw, drill a hole about 2" from the heel of the butplate! roll the coarse thread screw in a bar of soap to slightly lube the screw, and hand screw the coarse thread screw into the stock.   if you have reservations about possibly damaging your stock, take it to your gunsmith who will drill the hole for you. some 'smiths will actually install the swivel mounts at no charge if you purchase the swivel mounts from him!  good luck!