If it is the correct sling swivel for target shooting, it will not turn past the loop on the trigger guard. You can observe this in the photo above. This prevents the sling getting twisted. The sling in the photo is not properly set up. You can see the twist between the swivel and the arm. To avoid this, the sling must actually have a 180 degree twist when it is hanging loose, and NOT the "all-square" parade-look. Awkward to describe, but try it out and you will see what I mean. And to keep just that 1/2 turn twist, you must have the type of swivel that will not rotate past the loop!
However, there do appear to be longer swivels around, that pass over the loop. I am not sure if these are fake, or just simply a variant, but if you have one, I advise you to shorten the screw shank* to achieve the desired effect mentioned above.
Patrick
*That will probably require the thread to be extended down the shank, to achieve the same thread length - it is 1/4"x26tpi (1/4BSF, before anyone asks!)