Is it a good idea to fly with flashbulbs? For example, is it possible that X-ray checks could ignite them? A suitcase fire would be a pretty nasty experience. Or probably airport officials believe that they are potential explosives and will refuse you to board the plane if they find any flashbulbs? With all the post-9/11 paranoia, the security regulations are somewhat tighter, and the fact that people in 1960ies probably flew quite happily with all the flashbulbs they would ever want does not mean that the same thing is possible today. What is your experience (if any)?
That is an interesting question. I would guess it just MIGHT set off the bulbs.
You might try contacting someone directly at the airport, but knowing the rampant stupidity and idiotic attitudes of "if you ask, you gotta be up to no good" here in the USA, you might find yourself under heavy suspicion for trying to do the right thing.
The only thing that is going to unintentionally set off a flash bulb is a static electric charge. This could be present around any piece of electrical equipment not only x-ray equipment. The x-rays themselves will have no effect. If you are concerned then use a piece of aluminum foil to short out the contacts on each of the bulbs. This will prevent them from firing.
I've taken them interstate in Australia without any problems. No questions asked when it went through the scanner, even with the 3 cell Graflex gun sitting next to them.
My usual policy for things that may look unusual is to have them in my hand luggage so that I can pull them out and explain what they are rather than have somebody stuff around with my checked luggage.
Although I have never had it happen, it is supposed to be static electricity that sets bulbs off accidentally. So long as they are in their original cardboard packets or sleeves they should be fine and these also help protect them and identify what they are to interested officials.
Flashbulbs can be ignited by both radar and microwave, if the frequency is right and the intensity is high enough. IDK about X-ray, but I doubt it.
On one of the missions, an associate of mine was carrying 24 flashbulbs in his uniform and coat pockets when he walked in front of a jet fighter with electronics undergoing tests. All bulbs fired and he was burned by the heat.
Flashbulbs can be ignited by both radar and microwave, if the frequency is right and the intensity is high enough. IDK about X-ray, but I doubt it.
On one of the missions, an associate of mine was carrying 24 flashbulbs in his uniform and coat pockets when he walked in front of a jet fighter with electronics undergoing tests. All bulbs fired and he was burned by the heat.
PE
Ouch! Of course a fighter radar puts out a lot of power. I wouldn't stand in front of one without flashbulbs. There used to be a joke in the F-14 community that you didn't need a receiver to know you were being painted by an F-14 - the cockpit would warm up. I suspect that was a slight exaggeration.
Granted that a fighter puts out a lot of microwave energy, a commercial airliner nowdays does this as well, and so does the airport tower radar! My associate was at least 100 ft from the plane if not more. And, this took place in the '60s when fighter radar was weaker than it is now.
How close might your luggage come to an active plane radar? How much of the field of the tower radar might it encounter?
Since I have no idea, and the age of flasbulbs was dying at the time the age of radar was starting, we really don't have much data at all.
I hope that you see the unknown level of hazard which might be lurking here.
Radar emissions are strictly regulated and all attempts are made to keep them from being encountered by people, as they are akin to microwaves and can 'cook' things! They are not regulated as far as objects such as luggage are concerned.
Flying with flashbulbs? 
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