When practising I do get a pinch type pain in my hand at the base of the little pinky, never bruising. I agree with gredoniz when he says you need a relaxed manner. You can't force a solid ring to penetrate another ring you have to let it happen.
Have you got the dvd? Even when you see shoot do the spin pick up you can notice that he is quite near his hand. Also I had to practice just spinning the ring without the pick up just to get the spin stationary enough to make the pick up possible.
The one handed pick up flick I find just needs short sharp energy but not forced aggresion just in case my post was missread.
