Look at some of the manufacturer's sites about bake time. Some have time/temp charts that show the effect of different temps on the time to cure as well as maximum temps. Almost all of them had a decent cure time at 400F and there did not seem to be a max time at 400F. The higher cure temps had max times associated with them. Longer than max time at higher temps would result in a poor/damaged coating.
FWIW, the reason for the time/temp charts is production. High volume lines will use the cure temp that gives them the fastest cure time.
Make sure your oven runs at the correct temp. Know that there will be hot or cold spots in the oven, which is why a convection type is better. If you are running larger batches (basketful of bullets) then you will need a longer bake time (thermocouple in the center of the basket is highly recommended).
I'd rather not worry about it so I set the timer on my little convection oven for 23min (preheated), slide the tray of bullets in and let cook at 400F. Note: all of my bullets are cast in a single layer on the tray, most standing on the bullet base.