got a parker buckbuster 150 in the mornin is openin day for deer and bear and i didnt get the chance to pick up a rangefinder season kinda sliped up on me but anyway i have been getting a bear on my trail camera pretty regular and id like to try to take it with my crossbow in the morning i have a 12 ft ladder stand set up and the will around 15 yards from the bottom of my ladder do i hold low with my 20 yard pin if so how much?