I have a G-32 that I converted to a G-19 via Lone Wolf slide, 9mm ejector housing, etc. The gun is stone reliable, but it seems to be placing shots high on the target at 25 yards. I ordered a " - " sight for it, but I want to know if anyone else has this problem. The gun shoots high at all ranges, but it shoots WAY (about 6") at 25 yards. It does this no matter what ammo I use. I've used WWB, and 127 Grain +P+ and both group about the same place. I've yet to try Corbon's 115 grain (1350 fps).

Does it shoot high with the .357 Sig barrel?

What kind of sight alignment are you using?  Are you covering your target with the post or placing under?

This.  I align the top edges of the sights and then place the bottom edge of what I want to hit (bullseye) on the top edge of the front sight.  If you cover the bullseye with the front dot like is popular on some models of handguns you will often shoot high with a Glock.

I'm holding dead on. The bullseye cut in half by the sight picture. The front sight level with the rear. I can get hits if I do the old six o'clock position.

The gun shot to the point of aim with the 357 Sig slide and barrel.

I actually go off of the top of the sights, not the dots. The dots only come into play if I can't see the sights.

That's what I mean too.  I level the sights and center the whole bullseye over that plane of sight.