Given the max distance shooting distance in HFT is 45 yards a .177 caliber air rifle @ 11.4 ft.lbs using a Diablolo design pellet and zeroed @ 27 yards will cover the entire target ranges within 1.5 mildot of the reticule of a scope set @ 9X. The reticule in HFT is not that important so long as you have 1/2 mildot subtensions. The quality of the glass and lack of parallax are paramount though. Cheap scopes suck at this and only a few expensive ones actually overcome the parallax problem.
My advice is to get a as clear a scope that you can afford, preferably with 32~40mm objective, with a 1/2 mildot reticule and don't look back. Practice and knowing your equipment makes all the difference.

A.G