A method of manufacturing a gas turbine engine element, for example a shroud segment. An insert has at least one elongated feature received in a mold cavity. A powder injection molding feedstock is injected. When the green part is disengaged from the mold, each elongated feature is slid out of the green part to define a respective elongated passage. The cross-sectional dimension of the elongated feature may be 0.020 inches or less, and/or a ratio between the length and cross-sectional dimension of the elongated feature may be at least 25. The method may include, after debinding and sintering, projecting a coating material while defining an obstruction between source of coating material and the open end of each elongated feature with a shoulder of the element to prevent the coating material from reaching the open end, followed by machining to remove at least a part of the shoulder.