TheHossUSMC shares some useful knowledge about using cover effectively- by explaining how two different Syrian rebels failed to use cover effectively in some recent viral videos.
The fundamentals discussed here apply to both handgun and rifle situations. Using cover is not as easy as it may look- how often do you lean out of over or concealment to do anything? The average person would probably step out from behind cover like the guy in the first scenario – which is why you should practice using cover and incorporate it into your training regimen.
Here are the videos referenced in the HossUSMC video above- be advised that these are uncensored videos that may disturb some viewers.
Video 1 Leather Jacket Guy, die in style:
Video 2 Machine Gun Guy, die like an idiot: