You could probably get many different types of answer to this question. If you have a lower magnification scope or are using iron sights they provide a better aiming point than the thinner lines of the circle beneath the square box. To a lot of shooters the box is a nightmare. Even with a 6x18 scope I have trouble picking out the shot if it went in the black box.
Some shooters use different parts of the thicker black box as aiming points. Benchrest shooters are only concerned with group size not where the shots actually land, just so they're as close as possible to each other.
They may aim at the lowest left or right corner of the black box, but adjust the scope so the shots print well away from it for claritys sake. You'll probably get other answers to this question as well. Best wishes.
Cal - Montreal
