Dead center. A bull target can visually shrink or become bigger depending on the position of the sun. Target shooters generally often opt for a 6 O'clock hold, but also go by the rule of thumb "sun high, sights high... sun low, sights low" to remember to make adjustments to the sights based on the sun's position.

Dead center is always dead center regardless of the size of the target or the position of the sun.