I was wondering is there a set size for different circles to use at different ranges? I bought one of those BDC type scopes and wanted to check how accurate it really is. So i use a 1" circle at 100 yds then 2" @200yds. Do i just make the circle bigger one inch every 100yds? I was hitting the metal targets out to 500 yds but could not see the impacts to clearly to determine if i was hi or low. So i figure shooting paper would definately tell me if i was hi or low at those ranges and how much? Any input would be helpful.