We perform numerical simulations of cosmic string evolution with intercommuting probability P in the range 5 \times 10 ^ { -3 } \leq P \leq 1 , both in the matter and radiation eras , using a modified version of the Allen-Shellard code .
We find that the dependence of the scaling density on P is significantly different than the suggested \rho \propto P ^ { -1 } form .
In particular , for probabilities greater than P \simeq 0.1 , \rho ( 1 / P ) is approximately flat , but for P less than this value it is well-fitted by a power-law with exponent 0.6 ^ { +0.15 } _ { -0.12 } .
This shows that the enhancement of string densities due to a small intercommuting probability is much less prominent than initially anticipated .
We interpret the flat part of \rho ( 1 / P ) in terms of multiple opportunities for string reconnections during one crossing time , due to small-scale wiggles .
We also propose a two-scale model incorporating the key physical mechanisms , which satisfactorily fits our results over the whole range of P covered by the simulations .