Integral equation formulations are used for the modelling of axisymmetric perfectly or imperfectly conducting scattercrs (the Leontovich boundary condition is then assumed to be verified). Our emphasis in this paper is to consider bodies that are large compared to the wavelength. We outline the methods implemented, some of which are original. Particular care has been taken in order to suppress the spurious internal resonances and to minimize the amounts of computer time and memory storage. The numerical examples presented, performed on a wide variety of objects, show that a. high degree of numerical accuracy is achieved in the high frequency domain even in the angular range where the Radar Cross Section is low.