What about a tri-dot style sight?
If the sights have markings on them, you're limited in how much you can modify them without ruining the markings.
At 10 yards this weapon seemed to be shooting 2 inches low of center. After swapping the sights I was about .5 inches high at 10 yards. The problem is that one set of front sights puts me 2 inches low, the other .5 inches high. Ou to 25 yards is where I want to be, eventually.
Half an inch high at 10 yards is actually not bad at all. I would be happy with that kind of sight setup.
You have to understand that you won't be exactly on point of aim at all ranges, only for the specific range where you adjust the sights.
The sights are above the bore, and that means that the sight line and the bore line can't be aligned perfectly. For normal handgun ranges (out to 25 yards or so), the point of impact variance due to range is generally considered negligible.
Here's a post on the topic.