I have paid little attention to pressure as I usually have shot game at distances under 700 yards with a very flat shooting load. However, I am now shooting with a handgun and a much less flat shooting load. 29.53 is the default used by my Oehler Ballistic Explorer software. Two inches of pressure difference (to 27.53) change my POI by 2.8 inches at 700 yards. In your real world experience, how much variance can there typically be above or below this 29.53 default reading? How common would a 2 inch pressure change be?