You need to build your position behind the rifle. Most guys lie directly in line with the bore. Most critical is getting your head properly positioned behind the scope. Figure out where your head needs to be, then adjust the stock to your body so you are as relaxed as possible while in position. I like to start with all adjustment at their minimum values and increase them until they touch the appropriate body part. The goal is no muscle tension to support yourself. Try to achieve bone support, not muscle support.

If you don't know about natural point of aim yet, so a little search. In essence, you want to be able to close your eyes, relax, and then open your eyes and still be on target.

Another good trick is to set the rifle up with the bipod and rear bag so the crosshairs are on target and the reticle is level. Figure out how to approach the rifle and get into position while keeping the crosshairs on target. You'll need to squeeze the rear bag, or start with it high to compensate for the weight of your head. Finally, add your right hand, all while staying on target. Adjust the stock so this is comfortable. All that's left is to fiddle with your trigger hand to get a clean break while dry firing. Crosshairs should be dead still when the trigger breaks.