Flares (again)

[teleblaster]

It seems clear that flare firing points were mounted for safe discharge, ie not setting your own plane on fire! But I'm intrigued by some fixtures where the cartridges at least, if not the firing point are mounted outside the aircraft and even over the shoulder. This must have proved very difficult to access for cartridge retrieval (though not necessarily for pistol firing). There must have been many instances of cartridges being fumbled and lost. I wonder if this was due to fear of spare cartridge ignition inside the cockpit, either due to unreliable cartridge manufacture, or ignition by hostile fire. Does anyone know more about this subject?