As I understand, Glocks (and pretty much most manufacturers) are not "sighted in" at the factory. I bet your rear sight was installed either very late on a Friday or very early on a Monday. Or by a slackass who had a slackass QC person inspecting his/her work.
Myself, I would center the sight, eyeballing it. Measuring with a micrometer or calipers is not necessary. If you don't have a sight adjustment tool, and you do have a vise, wooden dowel, paper towels or old sock, and some kind of hammer or wood block, then you can easily do that yourself. Pad your slide. Clamp it firmly in a vise. Tap it with with a wood dowel and hammer until it looks just about right (centered). That is plenty good enough.
Then, if you are still grouping, and your groups are off of your point of aim, then look at this chart, and adjust your shooting technique to correct it:
![Circle Diagram]()
Myself, I would center the sight, eyeballing it. Measuring with a micrometer or calipers is not necessary. If you don't have a sight adjustment tool, and you do have a vise, wooden dowel, paper towels or old sock, and some kind of hammer or wood block, then you can easily do that yourself. Pad your slide. Clamp it firmly in a vise. Tap it with with a wood dowel and hammer until it looks just about right (centered). That is plenty good enough.
Then, if you are still grouping, and your groups are off of your point of aim, then look at this chart, and adjust your shooting technique to correct it:
