The scaling of the non-linear reconnection process associated with the m = 1 internal kink instability is studied in cylindrical geometry, using a three-dimensional numerical code with a full set of resistive MHD equations. In the presence of an ideal unstable kink mode, the non-linear evolution of the instability shows a transition from a purely resistive kink mode for high resistivity to Kadomtsev reconnection driven by the ideal kink mode for low resistivity. For the case of low resistivity, the assumptions of the Kadomtsev reconnection model have been checked, and the results confirm Kadomtsev's estimations of a scaling law of η1/2. A model is proposed to understand the transition and to compare the studies with previous numerical results obtained for different plasma parameters.