Your right there Ron.
My design looks as though its going to be a little diffrent, I have a load of 600v fets, 320v reflected will overvolt them slightly, and if theres a lot of ringing probably enough to destroy them, so I'm going to fudge the design to have less reflected voltage and lower duty cycle, this will up the primary current, but thats ok these fets are beefy to247 jobs, way overrated, also the rectifryer will work less hard as the discharge cycle will be longer.