You don't, you remove powder and caps from prop bullets so like loose ones sitting on a table, or for when a character loads a gun, close ups of mags and revolvers etc.
Then when doing shooting scenes, you unload those and load in blanks. If the armorer wasn't properly trained, they may have either used actual live rounds that got left in during a switch to blanks or just done a poor job of disarming the bullets.
I'm not sure I follow - how do you get the pop n smoke from the gun without the powder?
You don't, you remove powder and caps from prop bullets so like loose ones sitting on a table, or for when a character loads a gun, close ups of mags and revolvers etc.
Then when doing shooting scenes, you unload those and load in blanks. If the armorer wasn't properly trained, they may have either used actual live rounds that got left in during a switch to blanks or just done a poor job of disarming the bullets.