Imagine a knitting needle about 3 feet long, razor pointy sharp at the front and back with a very light bevel to the widest points and a very slight taper off to the end.
Now, think about how that wonderful, near perfect projectile used for establishing ballistic coefficients would fly? Now, think about that nasty, ugly stubby, crappy .117 pellet you are firing. Your question is like putting a 0-200mph speedometer on a bicycle and fretting about the calibration beyond 50 mph.
Ballistic coefficient, in real rifles - nobody much cares or gives a hoot until you are looking beyond 200 yards. With a .117 air gun, 200 yards is a dream.
Go find something more useful to try to and figure out.