Thanks Ian. For what I'm trying, the shutter can be open (complete darkness) and in that case, will the simple circuit I describe do the trick? There aren't any other components in a simple flash-bulb gun are there?
Try it out. The worst that can happen is success. I've done something similar with electronic flash. Lock the shutter open then run around in the dark firing the flash via the test button.
BTW: the big kid in my avatar is my hero, my son, who proudly serves us in the Navy. "SALUTE"