Ok, let's throw another twist into the equation. Not only is powder temperature sensitive the barrel harmonics will change with a change in temperature and humidity. Temperature will affect the the amount of flex the barrel will experience, humidity will affect the barreled action to stock fit. Now before you get your panties in a bunch yea, yea, yea I know not all rifles are stocked in kevlar or synthetic and yes even laminate will show some sign of expansion perhaps nowhere close to wood but some.