Bullets out has been gaining popularity lately because it tends to be more consistent as you reach further and further back past 9 o'clock. This can vary greatly, though, based on body shape, for example.
In Limited and Open, it's easier for many to put the mags at an angle, like thermobollocks said, When you sweep your hand down toward your belt, the mag is in the perfect orientation. And as you sweep your arm back toward 9 o'clock, all your mags are at the same angle, relative to your arm. It may look and seem strange, but it works.