Since my English is not perfect, I assume that with bullet bursts you mean the nozzle fire from the guns and cannons ?
I so, I would considder using ver small amounts of cotton, glued to the nozzles of the guns, and then spray those cotton pieces orange and yellow.
I haven't done this myself, but I have been considdering this for my next diorama, envolving the rescuing of the crew of a Vietnam era gunship, by a Huey 1 C.
Keep us posted how it turns out...