Pneumatic Pnews

Monday, September 18, 2006

Red dot sights

by Tex Force

A reader named Pete asked for this, and I apologize for being a week late with it. He wants to know how accurate dot sights are and if they can be damaged by spring-piston rifles. I'll do my best to answer.

Originally known as infinity sights
The dot sight concept has been around for the better part of a century, now. They were first used by sportsmen on shotguns in the 1920s and '30s. Then they were applied to battle tanks and possibly aircraft. Tank gunners would sight through what was called the "infinity window" of their M60A1 tanks and whatever came inside the "ghost ring" circle of light was within the circular error of probability of their .30 caliber coaxial machine gun. In other words, you could hose 'em down!


A dot sight is a simpler optical sight that projects a dot at infinity.


In the 1980s, several companies revived the sporting use for the dot sight, only this time for rifles and handguns. Instead of a ring of light, they used a 5 mil-dot that was collimated (aligned) to a point where the bullet would strike. Since the dot is optical, it is easy to adjust where it appears, which results in adjusting for windage and elevation.

Accuracy
A dot sight is about as accurate as open sights. BUT, it's easier to use, because the shooter doesn't have to focus on multiple objects at different distances. As a result, there are certain handgun target disciplines that permit the use of dot sights in order to encourage shooters with imperfect vision to enter the competition. Adjustment of the sight is identical to adjusting a scope, with windage and elevation knobs located in the same place. Because of the dot's lower precision, the adjustments may be larger than those made on a scope.

Strength
A dot sight is simpler and built somewhat more ruggedly than a scope, in that it has no erector tube mechanism. It should, therefore, be somewhat more rugged. Indeed, I have never heard of one breaking from a spring gun's recoil, but that doesn't mean it can't happen.

Speed
A dot sight gets you on target faster than a scope. Because there is usually no magnification, the view through the sight is exactly how the target would appear to your eye. Also, both eyes can be left open, which increases the shooter's depth perception. Parallax is nearly eliminated, too. However, the downside of a dot is the precision, which is lower than that of a scope. That makes the dot sight better for fast hunting situations, while the scope is better for precision shooting - though, the closer the target is to the gun, the more the balance tips in favor of the dot sight.

Not as easy as it looks!
The dot is not always easy to see - especially on a handgun! Unless the gun is pointed in close proximity to the target, the dot will be impossible to see. So, it takes some getting used to. Once you get the hang of it, it's much faster to line up than a scope.

Modern advances
A modern dot sight has variable levels of illumination, so it can be adjusted to the shooting situation. The brighter the dot, the larger it appears and the less precision you have, so the rule is to go with as little illumination as possible. Dots can also be varied in size in some sights, and some have more than just the red color, with green being the overwhelming second choice. The finest dot sights have different reticle types for different shooting situations, and they can cost upwards of $300.

Compasseco sells three models of red dot sights under the Tech Force brand name: model 47, model 90 and model 96. These are all great values that are built to the most rugged standards possible. The 90 and 96 are actually built to military specifications.

A dot sight is a different way to enjoy shooting. It offers fast target acquisition and ample precision for hunting. You might want to give them a try!

5 Comments:

  • Tex,

    Thanks for a great report.

    Pete

    By Anonymous Anonymous, at 5:41 AM, September 18, 2006  

  • Tex,

    what are the advantages of "holosights" (like the one from Bushnell) that justify the price?

    Markus

    By Blogger Markus, at 6:45 AM, September 18, 2006  

  • Markus,

    Primarily the ability to switch reticles. The shape of the holosight was different when it first came out, though it copied the shotgun sights from the 1920s, but now there are many other sights that look the same ands cost far less.

    Tex

    By Anonymous Tex Force, at 7:36 AM, September 18, 2006  

  • Hey,
    Tex Force i like your blog.
    I have a question about dot sights?
    Do you think any of the dot scopes?
    You sell on this web site are strong enough?
    For an hw90 or rx2?

    By Anonymous Anonymous, at 1:42 PM, September 18, 2006  

  • The absolutely are. Both the TF 90 and 96 are Mil Spec'ed for ruggedness.

    Tex.

    By Anonymous Tex Force, at 2:34 PM, September 18, 2006  

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