Lets not forget that at target that stands still is not the same as a target the moves and never stays in one spot for more than a few seconds.
It sure not the same as target that moves toward you and shoots back.
Some people are getting confused. Propping up a pistol and getting head shots on a target at 50 yards in not that big of a deal for a competent shooter. Just because one can accomplish that fairly often does not mean that it should be tried on a person.
This is a gun forum populated with gun enthusiasts. I'd be willing to be that your assumption is a bit on the low side.but I would say less than 5 percent of the members of this forum could make a 50 yard head shot with a semi-auto sidearm with iron sights even off a rest with 5 tries at it.