Herein, we report the role of mechanical activation in modifying the structural, microstructural, magnetic and hyperfine parameters of nanosized Co0.3Zn0.7Fe2O4 having average particle size similar to 16.6 nm synthesized via coprecipitation method followed by high energy ball milling with cation distribution (Zn0.612+Fe0.393+)(A )[Co0.32+Zn0.092+Fe1.613+](B)O-4. The values of the blocking temperature and Curie temperature of the sample are 220 and 270 K, respectively. The values of saturation magnetization at 300 and 5K are 59 and 88 emu g(-1) and those of the coercivity at 100 and 5 K are 400 and 5000 Oe, respectively. The values of the magnetic parameters of the sample are greater than those of its counterparts synthesized by chemical methods. A model for precise estimation of the cation distribution of ferrites has been proposed. Moreover, the memory effect obtained in the dc magnetization of the sample can be used for generating, storing and retrieving binary bit pattern.