You're right , current limited source is better , here is my schematic , what's your opinion about this :


As the output of LM317 current controller is open , output capacitor The 47uf would charge to Vcc-1.2v .
after firing the Q1 that capacitor would give a big shock to the led for a very short time (i think it would be good to make it turn on fast) and then LM317 would take the control throught the loop ,lowering the voltage to reach the correct voltage for the 250mA regulated current source.
And the RC in the input of the 2N2222 would lengthen the short shock from the pickup transformer to something about 1 ms ?.
Is it better to use a FET (Lower on resistance and faster turn on) instead of 2N2222 ?

I'm planing to use some 5mm high intensity LEDs in parallel , or use some big 10mm's or power diodes.