As a skeptic, I firmly regard astral projections as a subset of lucid dreams. I.e. all astral projections are really lucid dreams, it's only the intent that is different.

People who AP feel strongly that they are literally leaving their body and interacting with the universe, but then again, so do lucid dreamers. The feeling in itself proves nothing, and as far as I know, there has been no instance of an astral projection actually influencing the real world in any way.

So until that happens, I'm gonna go Occam's Razor on AP's ass and say: APs are LDs.