Right please be gentle.... When shooting HFT I seem to hit all or nearly all of the 18 yard plus kill zones but struggle with the 8 10 12 ones.. So last night I set up targets at 8 10 12 14 16 and 18.... Guns (Platinum With a Lightsteam scope and a MK4IS with a Mamba lite) Both guns zeroed at 25 yards.. I had previously tested and written down all my aim points at these ranges but was keen to make sure they were spot on ready for Sundays shoot... Started with the Platinum at 8 yards.. Height was right but impact point around 10 mill to the right.. 10 Yards. Again height was right but impact point around 7 mill to the right 12 Yards.. Height right impact point 4 mill to the right. 14 16 And 18 were spot on and impact was dead centre..... Swapped to the Mk4 and had same results except the impact points were slightly more central but still just over to the right until 14 16 and 18 where again they were spot on.... Guys at the club say parallax error.... Now I have heard this term but never understood what it means. One Chap said the artificial lighting ? So turned them off and it stayed the same ! Tried adjusting the cheek piece and butt pads but again no change. So do I just shoot say 10 mill to left at 8 yards ect or should something be changed on the gun / scope set up ?? Sorry this is a bit long winded but the only way I can explain is how it happened Thanks... CF.