In this report two methods for estimation of the effect of muzzle brakes have been tested:  simplified recoil estimates based on gas flow alone  more complex recoil estimates based on gas and a bullet, both moving through and leaving, the barrel Both methods have used CFD for computation of the forces on the specified set of muzzle brakes. Simulations have been carried out on a segment of the full cylinder, using symmetry boundary conditions. Results show that the gas flow based method can be used to quickly obtain relative estimates of the eects of muzzle brakes.