Guess that is why we need to hit the range now, get rid of that old powder.........I tried this in my sons Handi rifle (243) last year.......I shot a group of 100 grain Rem cor lokt ( 3 shots each ) 3 times.......THEN , I shot a NEW box group, before I even considered changing the clicks on that scope,,,,,,,and yeah , I feel your pain...........I started hanging small waterballins on pushpins......watching them explode was fun....then when all that last year stuff was gone, I sighted in.........to me, the only thing that changed , was the wind.....I hardly had to change a thing....