I know three people with EMP's ,not one of them ran 100% out of the box.
I believe, (nothing to back it up with, just in general what i have seen, read and heard) that maybe 70% of 1911's will run 100% right out of the box, the other 30% have issues.
I have seen people post on this very board how their guns never malfunction, and how great they are, but then at shoots I have seen them all have hiccups.
I have owned maybe 12 auto loaders, only have four of them now. Only one ever ran 100% failure free. It was a Smif and Western Sigma, 9mm version. 2000+ failure free rounds.
I maybe can see how dropping a slide down on an empty chamber might could be harmful. I am not convinced but I don't care, its not like I sit around racking the slide all night long on my 1911. but for the life of me I can't understand how dry firing a center fire weapon can hurt the firing pin or spring.