Survival Laser C6 Duty Cycle

Hello,
I am planning to do a single mode 450nm build, with a Survival Laser C6 with an aluminum heatsink and a G2 lens, with an Osram PLT5450B with a copper module and a microboost at 275mA from DTR (should be ~300mW). What would the duty cycle be if I apply thermal paste between the module and the heatsink, and between the heatsink and the host?

I wouldn't think there would be need to put thermal paste between the heatsink and the C6 host but definitely around the module into the heatsink..
I'm guessing 3 minutes safe running it that low but it's up to you to get the feel..

Thanks for the reply, that's good enough . I just wanted to see if that heatsink had a good duty cycle or else I would buy the copper heatsink.

At that current you won't get a great deal of heat out of that diode. The thermal paste is really overkill.