On my range guns with fiber optic sights I've got .105 fronts and plain black rears with a .135 notch.
I just bought a new set of night sights for a Glock and went with a .125 front (the thinnest I could find with tritium) and a plain black rear with a .125 notch (4.25" barrel). This setup is pretty tight, much tighter than any other set I've had, but I'm interested to see how it'll work out and am gonna give it a try.
Depends on the barrel length but I like a lot of light around the front sight. Most of my 5'ish inch pieces have a custom made .100" front with the factory, Bomar, Novak, Millett or Bowen rear sight.
.125 front with the rear wide enough to allow good light on both sides of the front sight.
For the Glock 19 I have (yea I have one plastic gun) I put on the TruGlo TFO (tritium/fiber optic). They are just perfect for my eyes.
Unlike tritium night sights that can not be seen in the daylight and often the white dots will wash out in the shadows these sights can be seen in any light conditions. Have not measured them but they do have enough light on each side of the front sight blade to make precision shooting no problem...
Bob
The only Glock I own, a G21 gen 4, has these very sights on it as well.......
Main thing for ME, is lots of light on the sides of the front sight.
I usually take a needle file to the notch in the back sight.
For ME this makes getting on target LOTS faster.
Virgil B.
I use a .080 front with a brass insert and a .120 rear on my single actions. I like lots of light around the front and feel that the wide light gap helps with low light shooting for me at least.