Not in mine..... I made them solid, you don't want it to come "undone" while in use. There should be no "play" in the stud. The swivel will have some"play" that is the part that attaches to the sling, which you then attach to the "stud". The studs should be solid.
The back stud or the stud that is on the buttstock of the rifle is a "wood" type scew with a pointy tip, Pre-dill the hole a smaller size than the flutes on the screw but the same or smaller than the shaft of the screw, then screw it in.
The front stud or the stud on the fore grip of the stock will be a machine screw and will come with a "nut". The hole you will drill in the front of the stock should be the same size as the outer dimesion of the machine screw. You will then have to countersink the nut in the barrel channel, make this hole slightly smaller than the "nut" but larger than the hole you have already drilled through the fore grip. When you screw the two pieces together through the fore grip the pressure of the nut pushing into the wood or plastic should firmly set the nut. (you will notice that the nut has groves cut into it for this purpose). You will then have to mark the screw to cut it down so it does not impact on the barrel when it is re-installed on the stock.
Cheers!