depending on barrel length, there is a certain level of pressure remaining.... also depends on burn speed of the propellant. This dictates a bit of sensitivity as to hw the bullet exits the barrel.
Think of it as a tuning fork.... length, diameter... everything is a factor.
The crowns biggest factor in accuracy imho is sharpness and damage.
The best way I can describe it is walk on ice.... then slip on gravel.
Sharp edges of gravel kick your shoe out a bit erratically..... the same goes for bad crowns and bullets.