I find that either a round bull or a round bull with a white or red 2" center works well.

For a solid black round bull, I use a 6 O'clock hold. For the off color 2" bull within a bull, I hold for center. The I get a second crack at the same target using a 6:00 hold too.

I try a 12:00 hold to save changing paper but this is difficult at 50yds, not much trouble at, say, 25yds.

9:00 and 3:00 holds also work ok if you don't feel like heading down range, but they are not consitent for elevation.

With regard to wandering POI, I have found that a round bead is often the problem since the apparent center of the bead will shift with light. You will favor the side with more light, not realizing that the portion of the bead in shadow is even there. Filing the bead so that there is a flat facet facing your eye, with a bevel running from closest to the breach at the low point of the bead closest to the muzzles at the high side of the bead will give you greatest contrast for the bead and works great for hunting.

JPK