I wasn’t sure if this was “Balls Of Steel” or “Bad Gun Handling” and I’m honestly hoping the reason this fellow only winces is that they were using blanks for parade practice.
Which is why I put this in the “Bad Gun Handling” group. Sure the risk is a lot lower using blanks than real ammo – but there is still a lot of energy in a blank cartridge as well as a paper or wax wad at its tip to hold the charge in. At close range, or if you have an obstruction in the barrel, you should still seriously hurt someone or even kill them.
So treat every firearm like its loaded.
Keep you fingers off the trigger unless you intend to shoot what’s in your sights. (Which is what I believe happened here. The guy behind this fellow chambers a round while he has his finger on the trigger which immediately brings the hammer down on a live round.)
Learn trigger discipline and treat every weapon like its loaded.
Your life, my life, depends on it…
