To learn to roll with tools such as rifles and bars and to relax the shoulders start with a broom stick or even a broom. Sit on your behind and hold both ends of the stick. Now roll from side to side and forward and backwards avoiding hitting yourself with the stick or pressing it against your soft parts. Now Sit on one knee and do the same and than from a squating position. Change the grip to a shoulder width grip in the center and repeat the drill. Take care to watch your head and spine and look around as you move. Now hold the stick as you wish and place it at the back of the neck and repeat the drill, change to gripping the stick using your back and elbow pits (at the back) and see what solution you find to protecting your spine when your roll using this hold. Breath to relax and to start the movement in a better direction and than if you have a partner hold the stick in any way you like and have him move the stick as you balance yourself (while it is at the back of the neck or behind the back are good starting point) and roll if you need to. Remember that rolling is not something you do for it’s own importance. It is a tool to get somewhere and sometimes for fun.