Ballistic data for your favourite calculator — K31 + GP11 ord.

BC G7 (recommended): 0.276
BC G1: 0.549
Bullet length: 35 mm
Rifling twist: right 270 mm (~10.63″)
V0: 780 m/s @ 7°C
V0 variation: 0.8 m/s per 1°C

Range cards for the typical chassis setup

Sight height: 70 mm
Zero range: 100 m
Cartridge: GP11 Ord.
Click value: 0.1 mrad


It looks like this:

(Full user manual for the rangecards)