ND
I am ashamed to say that as a Capt I had my only ND. A soldier asked me to hold her weapon for a few minutes and passed it to me, I bollocked her for not clearing it first, showed her how to do it, pointed it at the ground, pulled the trigger - BANG (a blank round fortunately). In the adjacent line of open 4 tonne trucks the heads of the whole embussed battalion turned and looked at the smoking gun....
Two weeks later I made Major.
The General was very understanding about weeks without significant sleep on exercise and the months of irregular hours on operations before that. However...
Retired and years later, I now fly Vigies which only go bang from the engine.