What this is all about
Since many of the readers may not be familiar with sport shooting, and many of those who are, may not be familiar with one-handed precision shooting according to the ISSF rules, I will start this instructable with a short introduction.
Every online guide or book on precision pistol shooting strongly advice the shooter to focus on the front sight ― not the target, not the rear sight, but the front sight. When you are young, and have healthy eyesight, you can do this at will. However, once your eyes get older, and you discover that your arms have become too short for reading a newspaper, you will need help in form of a correction lens.
The reason a pair of ordinary glasses probably will not work, can be traced back to the rules. They stipulate that the pistol is held one-handedly. Due to the human physique, the most stable direction to hold out a gun with one arm is rarely straight in front of the chest. Individual variations make no fixed angle optimal for all, but most often the arm should point closer to parallel to the shoulders, than perpendicular to the chest.
Since a match can take close to two hours, and you would like to stay as relaxed as possible, it may not be a good idea to twist the neck enough to make the nose point in the same direction as the arm. Consequently, the shooter will look somewhat sideways. In order to obtain a view of the front sight which is as sharp as possible, the correction lens must be orthogonal to the line of sight.
In short, one-handed precision pistol shooting may require the shooter to place a correction lens at an unusual angle and position in his/her face. A special lens holder is therefore necessary.
Why not buy shooting glasses over the counter?
Naturally, when there is competition at a high level, and need for some gizmo to achieve better results, there are companies eager to fill that need.
However, these gadgets come at a cost. If you, like me, are not quite ambitious or skilled enough for justifying the plunge (straight away), but would like to experiment a bit, and see what a correction lens could bring, then this instructable is for you.
Excuses, excuses, nothing but excuses
Well, when I started this project, I didn't expect it to succeed. Now that it turned out to be good enough to write about here (though not good enough to tell my parents), I kind of regret not taking any pictures. It's not rocket science, however, so you should be able to DIY, just by looking at the end result, and read the text.
Step 1: Materials and Tools
- some cardboard
- one pair of el-cheapo reading glasses from the supermarket
- 1 mm thick clear polycarbonate sheet
The plastic sheet should be clear if you plan to use the lens holder in competitions. The ISSF rules prohibit the use of side blinders for pistol shooters.
- soldering pen with plastic cutting tip
- hot air gun
Step 2: Cardboard Prototype
Since sheet polycarbonate is cumbersome and expensive to work with, I honed in on the right shape with a series of cardboard prototypes. The position of the ear in relation to the eye is one parameter influencing the exact shape. The direction you look towards the target is another.
They can be cut quickly with scissors, and I think I made something like three of these before I switched to polycarbonate.
Step 3: Polycarbonate Work
Once the iterations in cardboard have converged on a definitive, one can start working with the polycarbonate sheet without fear. They usually come with protective plastic, on which one can write with a ballpoint pen.
A good pair of scissors can easily cut through 1 mm polycarbonate. The hole through which you will look is more easily cut with a soldering iron with a plastic cutting tip. The edges can be cleaned up with a sharp knife.
Note: This hole is better cut after the holder has been bent to shape! You will soon realise why.
It is a good idea to pay some attention to the edge closest to the ear. Most people have thin skin there, and would appreciate to make it nice and smooth.
Step 4: The Lens
The right strength is selected in the store, simply by trying several pairs, looking at something at the same distance as the front sight. Do not bring your pistol to the store, people will make a fuzz.
I picked a minimal design, for two reasons.
- A small lens = minimal weight to be carried by the friction between your ear protection and your head.
- With no frame, the lens can be extracted by simply cutting away the unwanted parts with the soldering iron.
El cheapo glasses can be close to 100 % plastic. This is normally less than ideal, but a real bonus in this context. My project produced very little waste.
Step 5: Tuning the Holder
Well, this is just an iterative process of heating the polycarbonate, bending it, then checking if the flat surface where the lens will be, is in the right position.
Since we haven't cut the hole yet, we can mark the centre with a small ring. This mark will help us position the lens-holder flat in front of the eye.
The correct angle is also critical, but I did not improvise any special device for getting this right. I simply tried to judge the result by looking in a bathroom mirror, and by peering at the edges of the lens-holder flat.
Step 6: Final Assembly
Well, how hard can it be?
I usually attach the rubber band closest to the arm first, in order to reduce the risk of smudging the lens when putting it in place. Finally I add the rubber band closest to the nose.
Step 7: Observations, Pros and Cons
Without any corrective lens, I can only keep the front sight sharp for short periods of time, when well rested, and in good light. For most of the time, the target tends to be the only sharp thing in view. (Sometimes I can even see the 4.5 mm holes against the black centre spot, 10 m away.)
I haven't used it for long, and I am a miserable shot, so it's hard to say if it made me any better. However, now I see every tiny error I make, so maybe it will pay off in the long run, simply by providing better feedback.
- Even though the described device is far from optimal or professional, the difference was mind-blowing. Suddenly I can see every tiny tremor, not only my own, but also those caused by gravity waves.
- The position of the lens in relation to the eye is easy to adjust. Simply push and pull the device around. It is only held by friction. Since the line of sight is at an angle, pulling the device forward, will displace the lens to the left in relation to the target. Pushing it back, makes the lens move to the right.
- The material cost is low, and the device is simple to make.
- You can try if this is any good for you, testing the water before taking the plunge and buy the real thing.
Using it, you will look like someone writing award-winning instructables.
- It can sometimes start to vibrate, which can be somewhat distracting. This can surely be cured with some alteration of the design, but I fear this could diminish its simplistic beauty.
- Only some parts of the position and orientation are easy to adjust. Those which are not require tedious and imprecise iterations involving a heat gun.
- The position has to be found anew, every time you use it.
- The el cheapo reading glasses only come in a small selection of strengths. You risk using something which is far from optimal, adding eye-strain. You may not last a whole match using it.
- Using it, you will look like someone spending too much time at www.instructables.com.