by Tom Gaylord, a.k.a. B.B. Pelletier
Tech Force TF90 dot sight
This report covers:
• Tech Force TF90 dot sight
• How does a dot sight work?
• Easier to use than open sights
• Not the latest and greatest
Tech Force TF90 dot sight
I was right there when this Tech Force TF90 dot sight was being designed. I watched it evolve over several years of development, as each new model was revealed at successive SHOT Shows. I even tested a forerunner of this sight in the 1990s for The Airgun Letter by mounting it on a Beeman P1 pistol.
The Tech Force TF90 was developed by Compasseco, who used a Chinese optics factory that also made sights for their military. According to Duane Sorenson of Compasseco, the optics and manufacturing details of this sight were superior to similar Chinese-made dot sights because of who built it. In the 1990s Compasseco did a lot of business in China and had enough influence to get products designed to their specifications, and Duane was especially proud of this sight.
You can see from the picture that the outer shell of this sight is square, yet the optics are round. The objective lens is 28mm in diameter, which is in the middle size range for today’s dot sights. Still, when you look through the sight, everything is clear and sharp, because the optics are very clean and there is no magnification.
The base is adaptable to both 11mm dovetails as well as Weaver dovetails. Everything you need comes with the scope, including elasticized square lens covers. It can fit on a wide variety of airguns and firearms.
The base is integral with the sight tube. There’s nothing to do except clamp the sight to your airguns or firearms, and, yes, this sight should work well on firearms of at least the rimfire class. You’ll need a recoil stop if you mount this on a gun that recoils and use the 11mm mount base, because it has no stop built in. The Weaver base takes care of that, of course.
Here, the Weaver base has been installed. Note that the rear screw hangs below the base and engages the Weaver or Picatinny slot to serve as a recoil stop.
The base hardware can be swapped to make the base fit 11mm scope dovetails, too.
This is a very small sight. It’s only 4-1/2 inches long, and the clamping base is just 2-3/8 inches long. That makes it ideal for those vintage air rifles that weren’t really made for scopes but have 11mm dovetails for peep sights. I mounted it on my Hakim rifle and there was room to spare. Now, guns that are difficult to scope — such as the vintage Walthers, FWBs and Dianas — can have this optical sight installed.
The adjustments are the same elevation and windage knobs you’ve used with scopes. I don’t have any information about how far each click of the adjustments will move the 3 MOA dot, but I’ve been adjusting it as though it has quarter-minute clicks, and so far (at 10 meters) it seems to have adjusted correctly.
What appears in the first picture to be the adjustment knobs are really caps. Remove them, and the knobs are adjusted with a screwdriver or coin. The clicks are very precise in both directions. The scales on the knobs, however, have no corresponding reference marks on the body of the tube. So, adjusting the sight is a matter of counting the clicks for each adjustment.
The dot’s adjustment knobs are operated by a screwdriver or a coin. The clicks are precise, but there’s no reference scale on the sight’s body to register where you’ve adjusted.