A heat shield panel for use in a gas turbine engine combustor is disclosed. The heat shield panel includes a hot side defining a first surface having an outer perimeter, a cold side defining a second surface spaced from the first surface, a rail member disposed on the cold side proximate a first portion of the outer perimeter, the rail member having an outer wall and an inner wall, and an orifice extending through the rail member, from the inner wall to the outer wall, the orifice having a cross sectional area that increases from the inner wall to the outer wall.