I have a 2-7x wide view Redfield on a 700 BDL Custom in .308 Win. that hasn't been shot for about 20 yrs. I went to the range, and had problems getting it on paper @ 20 yds!!! Does anyone know what the adjustment is on the old Redfields? 1/4", 1/2", other? The adjustment is smooth and it has no audible clicks. Thanks.