Revolver security piece

This is a security piece for the new security approvals of the german shooters confederacy (Deutscher Schützenbund - DSB), in which you´ll have to cover all chambers of your revolver during transport or when laying your gun down. Who the f____ made this approval??
Due you don´t see if there are bullets in the chambers while they are covered with this damn thing, my design has hollow pins to go into the chambers, so you can see that they are empty. The red flag has a hole to mount an even bigger red flag if your nitpicking supervisor thinks that it´s not big enough to see. *rage*

This design fits the Smith and Wesson model 686, by the way.
EDIT: Also seems to work with Colt Python (Thanks, Zetif)

V2 is a version without holes, just with short dummy cartridges. Some Pictures show Version 1, that was a bit too wide but worked the same way