The short answer, you don't, not necessarily for optimum accuracy. However, longer consistent shot strings and more efficient air consumption will result from a well balanced tune, which often requires adjusting both hammer spring tension and the reg set point. I am not very knowledgeable on your rifle, but I don't believe the hammer spring tension is easily adjustable. If the reg is externally adjustable, then I would think small adjustments could be made without the need to adjust the hammer spring. I'm sure someone with specific experience with the Sniper will chime in with the answer.