TFO = .195 high front sight (measured from top of slide to the top of the sight), needs at least .286 - .294 rear total height (measured from the bottom of the dovetail to the top of the sight shoulders).
I got a .272 high http://www.ameriglo.net/sites/defaul...s/gl405pra.jpg
(Ameriglo 406 PRA), so I'm .015 low, and I've been shooting a few inches low at 25 yards. (Previously at 6" groups at 25 yards with TFOs front & rear). I tested at 3 - 10 yards and it was consistently a little low there too. You are shooting the GL-205L which is .256 high. That puts you low at a difference of .030 That's double my deficit, so I can imagine you'd be hitting quite low (given your grip, stance, distance, and ammo load have been consistent).
The only Ameriglos that would truly work with the TFO front are: (All are .287 high, but only .150 wide)
- Rear of the CAPS set
- GL-402 (discontinued)
Love the TFO, but it has come lose, even with loctite (blue) and I'm seriously considering whether or not the fiber optic bonus will really come in all that helpful for my needs. If I found myself doing more outdoor competition stuff, It would rock. But as an indoor defensive handgun set-up for low light, it's really the wider .180 rear notch that allows easy and fast front sight acquisition from the silhouette of a tac-light that is key. Under those conditions, I've tested and tested, and it's the very rare light condition that I can even make use of the tritium. It's all about the sight picture, sights silhouetted by your light source, and consistent weapon presentation (especially for home defense & CQB).
That brings up a point though,...will a .015 low rear sight really matter that much at close distances? Probably not. But, given that under stress, the best you can hope for is the worst you do in training, I'd want my weapon system to be as dialed-in as possible leaving the very least room for mechanical error (that's why we have Glock's in the first place, no?).
The TFO front has great features, but the rear, I find too busy and the notch too narrow for my liking.
Ameriglo, Warren, Trij, all make great "u" type notches for faster targeting.
It's just been a tough search to find a set-up that does it all.
Even using a Trijicon RMR would have its drawbacks.
I'm considering switching it all out to this: (Ameriglo GL-301 or 304 Green/Lime Green front & green or yellow rear) ProGlo-iDot
This set up seems like it would offer:
1. Fast target acquisition with a larger rear notch
2. Clear silhouette of the sight picture when using a tac-light at night
3. Brightly colored front sight for daylight conditions, or when shooting against a darker-colored target
4. Tritium just in case the twilight conditions are present
5. "Straight-8" type dot sighting for vertical alignment if needed
Too bad Ameriglo doesn't do the Tritium-Fiber-Optic combo. Probably a patent issue.