I tried to headshot some guys as i said,even dead guys, using a pistol and i got no dismemberment. Is it cencored or u cant dismember someone using pistol?
No, you cannot dismember with using the first firearm you get, and not even with the revolver, I think. You will need at least a hunting rifle for it.
Edit: Also the below answer is correct, too.
I have acquired the grade of Master in The Last of Us story/character/game knowledge as I have played it through 9 times.
... I have no life.