Originally Posted by
lensman57
Without trying to be a smart arse I really despair at some of the rubbish that is written about how the trajectory of a pellet should be calculated.
First of all the Max shooting distance in HFT is only 45 yards. At 45 yards an air gun firing a typical 8.44 grs pellet ( most probably JSB exacts ) @ 11.5 ft.lbs will only have a drop of 2" if the gun is zeroed @ 25 yards and 1.7" if the gun is zeroed @ 30 yards. What this means is that if a killzone of 15mm is specified, from 16 yards to 31 yards no real correction needs to be given.
A typical scope @ 8X ( the most common mag setting for HFT ) will cover from 17 yards to 47 yards within one mildot of the reticule, the 0.5 mildot will correspond to 38 yards with the exception of very close ranges , where 8 yards will require 2 mildots and 10 yards only one mildot of correction . The scope height for these calculations was set at 4.5 cm which is the most comfortable height for a 44 mm objective scope for an average guy but everyone is different so a little experiment is needed to match the scope to the gun and the shooter. Increasing the height to 50mm will really only affect the close ranges adding an extra half mildot to the above values but as a rule I wouldn't recommend too high a scope height as it will make prone shooting ( most of the shots are taken in prone position ) rather uncomfortable.
Hope you will find this useful.
A.G