POI will depend on the ammo to some extent but for my part having tried a lot of different brand 115gn ammo I found it to be consistent.
Your desire to have the POI coincide with the flush top of the front sight is how the guns are set up as they come. When I aim I use the top of the front sight to split the bullseye dot and, assuming I do my part, it puts the bullet right at the middle of the bullseye. What I get in reality is a bit of a cloud around the bullseye but that's me. The groups are centered properly based on this top of the front sight practice just as you described.