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In fact, it is mainly to help myself remember. I also hope to help some friends choose sniper sights. The content is boring. I am not interested in precision shooting and my friends who play AK will go around directly. If there are problems, I will call animals. The level is limited. If there are mistakes, please correct them (such as terminology translation).

Does the scope division need lighting?

This is basically a personal preference. Illuminated sniper mirrors are generally more expensive, but the advantage is that it is easier to see the division in strong light or dim environment. It is very useful in 15 minutes at dawn and dusk, because the strong light but the wind force becomes smaller at this time, which is a good time for medium and long-range shooting.

What are SFP and FFP?

The vast majority of mirrors are SFP (Second Focus Plane), which means that the division (aiming line) is engraved on the eyepiece at the back, so the division size is fixed and does not change with the change of magnification. The advantage is that the division size can be optimized, the thickness is just right, and the disadvantage is the differentiation function. For example, BDC,Mil Dot(BDC and MilDot will be explained later) can only be used at high magnification. (In fact, it can be used under low magnification, but the calculation will be very troublesome)

FFP ( FirstFocus Plane) is Gao Fushuai's choice. With the same lens, FFP will be much more expensive than SFP. It is scribed on the front objective lens and changes with magnification. The advantage is that the division function can be used at all magnifications. The disadvantage is that the division will appear very small at low magnification, especially under strong light, which is very difficult to see clearly. If FFP mirror is selected, it is recommended to select illuminated mirror.

The division of FFP changes with magnification, and the size of SFP is fixed.

Common sniper mirror division optical sight

Simple crosses. Not recommended. If the score is too thick, it will cover the target and affect the accuracy. If the score is too fine, it cannot be seen clearly in complex environments, such as jungle or strong light.

　　Duplex

Duplex division of 3 different thick lines

Improved on the Plain Crosshair, the line of sight is thin and thick in the middle, which not only makes up for the shortcomings of the above-mentioned cross division, but also makes the eyes involuntarily focus on the quasi-center. And it can be used as a simple dense site according to the length of the thick and thin crosshairs. It is recommended to friends who only hit within 300 meters and do not want to calculate ballistics, but only Holdover by feeling (aiming at the target for ballistics compensation by feeling). Leupold invented this division, but now many companies are doing it, each with a different name. Leupold-Duplex, Nikon-Nikoplex, Burris-Plex, Bushnell-Multi-X, Weaver-Dual-X, Steiner-7B.

　　BDC/Ballistic Reticle

On the basis of Plain Crosshair or Duplex, BDC (Bullet DropCompensation) points are directly engraved on the lens. It is recommended to friends who often play a bomb within 500 meters and do not require high precision. The advantage is that it can be aimed quickly without any ballistic calculation. For example, it is good to hit a 300-meter target and directly aim at the target with the BDC point corresponding to 300-meter. The disadvantage is that most of the marks do not have wind deflection points, and the correction of wind deflection depends on the wind deflection knob.

Small number of Ballistic/BDC zoning belt wind deviation point

In addition, BDC division has low versatility, and the accuracy of aiming with BDC points is not very high, because BDC is made according to the trajectory of a specific bullet in a specific environment. Any factors affecting the trajectory, such as altitude, temperature, humidity, changing bullets and guns, will make BDC inaccurate. (Although the same caliber projectile, the deviation between the medium and close range is not large). In fact, if you want BDC function, you can order the BDC knob. Because it is much easier to change the BDC knob than to change the BDC score.

A partition with small black dots (dense sites). I think it is a comprehensive and good division at present and recommend it to everyone. Most snipers now use this kind of split or a split based on Mil Dot improvements. Dense site division can be used to calculate distance, wind deviation, lead (Lead), and bullet drop (Bullet Drop). Focus on this division.

What is Mil?

Mil is the unit of angle, similar to MOA(Minuteof Angle), the distance represented by the increase in distance also increases accordingly. 1MOA = 1 inch at 100 yards = 2 inches at 200 yards = 3 inches at 300 yards, and so on.

1Mil = 3,438 MOA

= 3.6 inches at 100 yards = 7.2 inches at 200 yards = 10.8 inches at 300 yards and so on

= 1 meter in 1000 meters = 2 meters in 2000 meters = 3 meters in 3000 meters and so on

1Mil at 100 m represents 10cm Mil increases proportionally with distance

Calculate distance by Mil

There are many formulas, the simple ones are:

The actual height or width of the target ÷ the number of miles of the target in the scope × 1000 = the target distance

For example, if you see a girl, you know that the girl is 1.6 meters tall and you look at her 4 Mi in the sniper mirror, then the distance between the girl and you is

1.6 ÷ 4 × 1000=400 m. If you calculate by code, the unit is also code.

The difficulty is to first know the actual height or width of the target. This is also why snipers will note the height of some buildings, trees, telephone poles, etc. when surveying. (But now basically use rangefinders)

Leupold improved Mil Dot division actually has the function of BDC differentiation

Correction of wind deflection with mill (Windage Adjustment)

The formula is

Distance (hundred yards) x wind speed (miles per hour) ÷ 35 = corrected wind bias (Mil)

Simple rough point calculation, for 308(7.62NATO) bomb,

　　100米=0.1Mil(every 4mph)

　　200米=0.2Mil(every 4mph)

　　………………………………

600 m = 0.6Mil(every4mph)

For example, if you hit SCAR17 with a caliber of 7.62NATO, with a distance of 500 meters and a wind speed of 12 miles per hour, then the corrected wind deviation is 0.5 ×(12 ÷ 4)= 1.5 Mil

Constant 0.1 after 700 meters

For example, if the distance is 800 meters and the wind speed is 8 miles per hour, then the corrected wind deviation is (0.8 01)×(8 ÷ 4) = 1.8 Mil

Not very accurate but much faster. Mil Dot originated in the military. Compared with police sniper, military sniper is generally less demanding on accuracy, but more important to aim and correct ballistic speed.

Calculate lead in mils (Lead)

There are many factors that affect the advance, and the calculation is a little complicated. But within 600 yards, yes. The 308 175-order bullet hits a normal walking target (3 miles per hour), usually holding over 2Mil in the reverse direction when walking on the target. If you walk diagonally, hold over 1.5 Mil.

In case of wind, hit the 308 bomb and aim it at the normal walking target with the second Mil point from the middle number.

Scope height angle compensation (Up/Down Compensation)

If the shooting and the target are not in the same horizontal plane, the above mil calculation distance will be biased. Specific deviation to calculate ballistic. But the estimation formula is

45 ° angle, actual distance ≈ measured distance × 0.7

30 ° angle, actual distance ≈ measured distance × 0.9

A good ballistic calculator, of course, but it's expensive. You can use MilDot Mater.

Like a ruler, MilDot Master is a simple ballistic calculator

It looks complicated, but it is actually very convenient to use. Below is an example.

Distance (code) 100 150 200 250 300 400 500

Bounces (inches) 2.1 1.8 0 -3.4 -8.7 -25.1 -50.7

Go hunting and find a deer that shows 4.5 mils in the sniper mirror. You know this deer is generally 48 inches tall. It's ballistics from the gun egg in your hand. So how do we hit this deer?

(48 ÷ 36) = 1.33 yards 1.33 ÷ 4.5 × 1000=296 yards ≈ 300 yards

According to the above ballistic information, the 300-yard bounce is 8.7 inches. 8.7 ÷ 3 ÷ 3.6 ≈ 0.8Mil

It is not easy to calculate without a calculator. It is much simpler to use Mildot Master.

As long as ballistic information is available, the bounce compensation (BDC) calculated with MilDot Master is very fast and the deviation is small.

After that, you can directly use the corresponding dense point as the aiming point to shoot. Or raise the high and low knob (Elevation Turret) by 8 squares (for the 0.1Mil knob) and then aim at the target with the center of alignment to shoot.

I think the Mil Dot and its modifications are good sniper scopes for the vast majority of people. Mil Dot high versatility. The same Mil Dot divided sniper mirror can be used with any gun and any bullet. And can quickly and accurately calculate the distance, bounce compensation and correction of wind deflection. Especially when MilDot division is used with BDC knob, Mil Dot is used to calculate the target distance first, BDC knob is directly adjusted to the corresponding distance, and then Mil Dot is used for fine adjustment to correct wind deviation, advance, etc.