If you use the T1 as your primary windflag, you should use this formula: T*0.33, where T is target distance. The resulting distance is the placement from your position to where you should place the T1.
The reason for the 1/3 rule is the ballistics changes caused by wind between the muzzle and this traveled distance, have about 65-70% of the total change of the entire distance.
Put in perspective, if there was a 10mph cross wind from the right in the first 1/3, and a 10mph cross wind from the left the rest of the way, the poi would still not quite catch up to zero.
Below is an example using a target at 50m, resulting placement distance using the simple formula which nets a placement just shy of 17m.
The caveat to this rule is particular local conditions. In particular high localized buildings/structures may justify moving the T1 further out or closer. In some areas a small wind strip very close to the bench is a good idea to get a read of the turbulent wind drafts around the muzzle caused by these structures.
Due to the nature of ballistics, calibrating the T1 directly to a rifle and ammo combination is not very practical as it would only work with that combination at that particular distance it was setup with. So a much better way, and the one we recommend for maximum usability is the inverse calibration method.
It only require two steps.
Note. In this article the T1 has been setup so that it will show you where to aim.
Step one is to set your T1 up to be as sensitive as you would like, which is explained in the user manual.
Step two is as simple as setting the T1 up at the given distance, you can use an anemometer if you like, but not needed. Make sure there is some wind present on the range. Aim squarely at the bulls eye, look at the T1 and note the holdover deflection.
Whenever the T1 shows that sight picture your POI will always be the same.
So if you set it to be very sensitive it might look something like this:
If it is set to be less sensitive for places with heavy winds, it might look something like this:
The point being, consistency, the deflection on the T1 will always be the same, so all you need to check is what that equates to in terms of drift at the distance and caliber you are shooting. Which is done by shooting a few string in the wind observing the T1's sight picture.
An example, caliber .22, 30 FPE, at 50m. Your T1 has been set to medium sensitivity.
The wind is blowing 8mph steady from the right, or 3 o clock as it were.
You take 5 shots aiming at the center bull, you end up with something like this group:
Now you know that if the T1 shows you this sight picture, (deflection), this is the type of group you will get (drift), so now you have a very good idea about what holdover this equates to. By aiming like the T1 suggest, you will move that group into the bullseye much like this.
How much you need to holdover in the direction the T1 shows, depends on the distance and what you are shooting with. By direction I mean the imaginary line made up by the center of the T1 Sight picture and the holdover indicator, like this:
Depending how far you are shooting, or what caliber/bc you are using, you will have to adjust the holdover amount in the indicated holdover line by the T1.
In the examples above the magnus effect is accounted for in a typical right hand twist, with JSB diabolo pellets. Which causes more ballistic drop when encountering wind from the right, and less drop when coming from the left. How much effect this have on your particular setup depends on pellet weight, spin rate which is not only determined by the twist rate, but also the velocity of the pellet. So the only real way to accurately account for this in the T1 is using the above mentioned steps.
Making adjustments to the magnus effect indication, is simple, and outlined in the manual.
As most seasoned target shooters know, ballistic drift is a linear function of wind velocity, so for example, if you get a 1" drift in 10mph, you get 2" drift in 20mph at the same distance. That knowledge is applicable to the T1 as well, the movement of the ball due to its spring is close to this. Which means if the ball moves 2" in 10mph, it moves 4" in 20mph.
If you need extra sensitivity at sub 1-2 mph, the T1 has a groove cut into the tip of the sight picture arm where you can hang a string, or tail, or anything that will indicate the minutest of mouse farts. Useful for those who shoot LV or HV.
Leveling the tripod
The T1 is self leveling front to back, so no need to be super concerned about leveling it front/aft. Side to side leveling is more important, but no need to get it super accurate, but enough so that the sight picture isn't canted.
The easiest way to align it to your bench is to aim the indicator ball/crosshair towards your shooting position by using the tripod controls.