very high swirl residual
 

I am doing an axisymmetric swirl model simulation with reynolds stress model. The model involves high speeds( around 80m/s). I have slightly high swirl residual values i.e. 4*10^-4. I have had similar values of continuity residual before I started using extremely low values of courant number (0.8 is currently in use) which has lowered it to 1.06*10^-8. I have attached a screenshot. Is it good enough convergence or I should do something to get better convergence?