A method of forming metal castings, including positioning a first end of a structural member in a first mold cavity and a second end of the structural member in a second mold cavity. The first and second mold cavities being fluidly coupled to a reservoir of molten metal. Applying a main pressure to the molten metal in the reservoir to force the molten metal into the first mold cavity and the second mold cavity. Then, applying a first auxiliary pressure to the first mold cavity and a second auxiliary pressure to the second mold cavity to densify the casting formed in the first mold cavity and the second mold cavity. Also, a method for casting including maintaining a main pressure at or less than an initial, mold-filling pressure after first and second mold cavities have been filled. Additionally, a method for detecting whether a first mold cavity is sufficiently filled with molten metal by monitoring a moveable element.