Just spent a few interesting, and painful, hours on the flare gun.
Someone succeeded in screwing up the trigger mechanism. Took a while and a lot of painful fingers to figure out what went wrong: the trigger guard needs to be compressed (front to back) in order to pull it out, this will take the trigger spring with it. Somehow the trigger guard got partially depressed and the trigger spring escaped somewhere into the mechanism.
Bit of a puzzle to work out how to dismantle the thing and how to get it back together. It's a bit of a wrestling match but I got it back to work in the end. Very tough main (hammer) spring, not very nice on a set of rheumatic fingers…
You have to install the trigger, trigger spring and trigger guard in one go, but the trigger guard also needs to catch behind 3 pins. In the end I installed the trigger first, then partially installed the trigger guard, placed the spring between the guard and the trigger with a pair of tweezers and then clicked the whole batch in place. Spring doesn't cooperate and tends to escape at the worst possible moments. I ran out of my years supply of curses in one hour
