A lot depends on the rifle/barrel and of course the pellet weight . my rifle runs 770 in the summer but winter requires 785 . not a lot is it but it makes a difference . mostly to the windage , maybe two clicks difference on the longuns . remember the slower you run the gun the more effect it will have . 7.9s running faster shoot flatter , so 15 to 20 feet per won't make a lot of difference height wise , but probably will for windage on the longuns and the mini kills . trick is to get your own chrono and check it every time out . if you are using a springer not so easy cos in the winter the cold effects the grease and slows the internals . if shooting HFT . try taking a shot as a warmer before taking the shot on target . the slower your gun runs the more clicks you will have to add andthe higher your trajactory will be . thus more windage . ??? HOLLY
" Be your self , everybody else is taken "