Cringe worthy Moment

At least to me, was when they were training with their weapons. One of the team is shooting a revolver and he slams the cylinder into the frame by flicking his wrist.

This is extremely hard on the gun, yet it is still seen in many movies, I suppose because it looks professional, but only to those who don't know guns.

Admittedly minor, but I still cringed when he did it.