The phrase "more dead center" refers to something that is closer to the exact middle or midpoint. Some synonyms for this expression are "closer to the mark," "more on target," "more on point," "more accurately positioned," "more precisely located," or "more perfectly aligned." These synonyms convey the idea of something being placed more accurately or precisely, and being closer to its intended location. Using these synonyms can help to communicate a more precise and descriptive meaning, which can be useful in a variety of contexts, such as engineering, navigation, or art and design. Ultimately, whatever the context, the goal is to be as accurate and precise as possible.