I agree with therewolf on a copper fouled barrel.That will really affect accuracy. If your have any green or blue colored patches when you clean your barrel,it is copper fouled. There are many good solvents on the market to clean the copper from your bore,and since this is a new rifle,that could be your problem.
You also said you shoot the rifle better prone,than from a bench. Your line of sight through the scope changes when you change your shooting position,and that can also cause accuracy problems.You need to keep the same cheek weld against the stock in order to shoot the same in different positions.That just takes practice,and you may need to get a cheek weld pad for your stock to help you with that problem.