For a very long time all my slings ended with a medium-small knot on the release cord end which I held in the nook between my index finger and thumb. This seems to work ok- but recently I've been experimenting moreso with smooth release cords.
I know when gripping these knotless cords, you still use your thumb and index finger to grasp the cord, however I find that this is sometimes insufficient for heavier rocks and I need at least a little knot mid cord to ensure safe grip. I would like to move to or at least experiment with totally smooth cords here, as it allows variation in the retention finger and grip position.
I hear a lot of people say a nice thick release cord is easy for retention of heavy rocks but in my experience a knot seems essential, my index finger can't seem to grasp with enough strength to pin the cord by pure friction.
So, in terms of technique- even though you grasp with the pinch grip, do you also use your fist to hold the cord too? Or do you just pinch grip the cord with a deathgrip that even high velocity 200g+ rocks can't pull a cord clean from?
I would test myself, but slinging doesn't come easy in a big city