You need published load data to start. Go here:
http://data.hodgdon.com/cartridge_load.asp
Start load: 23 grains, Max load: 25 grains. Work up slowly and look for signs of overpressure.
Bullet Weight (Gr.) Manufacturer Powder Bullet Diam. C.O.L. Grs. Vel. (ft/s) Pressure Grs. Vel. (ft/s) Pressure
50 GR. HDY SP Hodgdon Varget .224" 2.130" 23.0 2884 33,600 CUP 25.0C 3114 40,600 CUP