Last year, during my RDS experiment, I ran a Glock 17 and M&P 9 FS with a RMR-02. I have followed the Unity Tactical Atom installation for the Glock, which allows you to mount a variety of optics, from the T1 to the RMR and future optics, using a series of changeable base plates. I decided to try a T1 on a Glock, since the T1 would seem to be the most rugged, weatherproof RDS available for mounting on a semi-auto handgun. A few weeks ago, I sent Mark Housel at L&M a G4 Glock 17 slide to install the Atom mount with a T1 and tritium back-up sights. I specified tritium reserve iron sights because I wanted something to help me acquire the dot in awkward positions and in the dark, and to use if the selected T1 setting was too low for the ambient light on a time critical shot.
The T1/17 slide was waiting for me today, and I couldn't wait to shoot it. First thing I noticed, handling just the slide, besides the quality of the installation, was the iron sights appeared to be low, and I couldn't see the rear tritium dots. Hoped it was a function of not being on the lower. Got it on the lower, and sure enough, the iron sights were unusable thru the tube of the T1. I spoke with Mark at L&M and Trent from Unity Tactical, and apparently taller tritium sights are in the works. Possibly the non-tritium Ameriglo sights are higher. The lack of usable reserve sights right now makes this a proof of concept, as I won't be carrying a red dot pistol without reserve sights.
I hustled out to shoot it. Round two was a stoppage, followed by about every other cartridge (Aguila 124 ball which runs well in our iron sighted Glock pistols). I took the pistol apart trying to figure out if something was assembled incorrectly, and while the pistol was dry, all appeared to be back together correctly. I replaced the extractor with an Apex G4 part, lubed it, and shot it again. It ran better, but I still had occasional stoppages. I then tried Lawman 124 TMJ and HST 124+P and had no issues. I believe that the weight of the T1, combined with the relatively mild Aguila, isn't a reliable combination. It is concerning, as it makes me worry that the weight of the T1 may reduce the reliability envelope of the host pistol, since this Glock ran fine, even with the old extractor, prior to the T1 installation.
I spent some time shooting groups, and it shot fine (about 3 inches) as would be expected, although my 25 yard groups were just as good with my reference G19 and 34 with iron sights. The weight of the T1 was noticeable, and besides the stoppages, the pistol felt top heavy to me. I them pulled out my RMR/G17 and shot it. I actually shot smaller groups (about 2 to 2.5 inches) with a variety of ammo, and felt more comfortable shooting the RMR/17. Not sure if it was the more heads up display of the RMR, or the prominent iron reserve sights. Interestingly, on 40-50 yard 8 inch steel, in good light, I really felt as comfortable with my Glock 34 and iron sights as the red dot pistols -- perhaps because I have been shooting iron sights almost exclusively since March.
Right at dark, I shot iron sights, the RMR/17 and the T1/17 again. Interestingly, where I preferred the RMR during the daylight, it bloomed badly at dusk, so that I had difficulty with the 40-50 yard steel. In the same light, my iron sights (Warren tactical rear, Heinie .235 tritium front) were near useless on the 40-50 yard steel. In the same conditions, the T1/17 was awesome, as I was able to turn down the intensity of the T1, and hit the same steel at will.
So what do I think -- I believe in the future of red dot sights on handguns, but I am not satisfied with either the T1, RMR, or other available RDS sights I am aware of for a handgun. Since I can see regular iron sights, and especially with the sight radius of the 34, I feel like iron sights are my primary sighting system. The T1 may have some application in difficult light, possibly with a -14 monocular at night, and in inclement weather, but I am troubled by potential for diminished reliability from the weight of the T1, along with more trouble with holsters and concealment.