After reading the article I wanted to know what is gained by shaking a bullet in front of the actor (this was not done but someone is quoted as saying it's stan

After reading the article I wanted to know what is gained by shaking a bullet in front of the actor (this was not done but someone is quoted as saying it's standard practice)? I found this which shows comparisons of bullets and blanks. There is a mention in one of the posts of BBs being installed to give a rattle. It says blanks are not to be used at close range and not to be pointed at anyone. A cold gun is supposed to be an unloaded gun and not a gun with a blank? https://www.quora.com/When-talking-about-bullets-or-rounds-what-is-the-difference-between-blanks-dummies-What-does-it-mean-if-someone-says-the-firearm-is-cold?share=1 https://www.quora.com/When-talking-about-bullets-or-rounds-w... But what stands out is how blanks and shotshell look the same. If the accident on the set used a bullet, that should have been visibly noticeable. The call was that it was a cold gun, but the article doesn't give an example of what was used. Anyone have info on that?