Real life snipers, i have a question for you

[Aculaud 0]

I was curious about the term Minutes Of Angle. What exactly does it refer to?

[USSoldier11B 0]

A minute of angle is a term used when dealing with the milliradian relation formula.

1 moa (mil) is roughly = to 1 inch @ 100m.

therefore, 1 moa @ 1000m = 10 inches

It is used for range estimation with a mil dot scope.

Here is the millaradian relation formula:

[width or height of target (inches) X 25.4]/ # of mils = range in meters

or

[width or height of target (meters) x 1000]/ # of mils = range in meters.

example problem: There is a man standing off in the distance, the average man is 5'10", he takes up three mils in you scope.

so....

[70 x 25.4]/3 = 592.66 meters to target

A sniper will then consult his trajectory card for bullet climb/drop at that range. If he is using a 168 grain match grade 7.62 x 51 NATO round. It zeroes at 600m. So, he doesn't need to adjust his scope. But if the target was at 800m, the trajectory is -90.8 from zero. He would adjust the elevation knob on his scope accordingly, or use the mil dots on the reticle to compensate.

A good rifle and shooter is considered to be someone that can shoot a group at .25-.5 moa. Thus, at 600 meters the deviation between each shot will be a maximum of 1.5 to 3 inches. Lat time I shot my Remington 700 PSS my best was .45 moa at 500 meters.

[christophercles 0]

the tango 51 has a .25 moa

[USSoldier11B 0]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">the Tango 51 has a .25 moa<span id='postcolor'>

The Tango 51 is a sweet, but also very expensive rifle.

I also like the Dakota Longbow. It runs upward of $4,000 U.S.

Sig makes a good one too.

PSG-1 is cool, but it comes with a scope that you can't change. Semi-autos just don't have the precision of a bolt action either.

My setup ran at about $2,000 U.S. all said and done.

[TheOmega 0]

Nice, i understand he wont.

To understand this, u must understand that this is a clockwork fine tuning activity in all aspects. Meaning every small detail is important. Easy to spot small details that make huge differences with a trained eye.

I will try to explain in a global manner so u can grasp the complexity (and simplicity) of this art. I will repeat the important points in different perspectives and try to simplify what is not. Problem here is that u r starting out from the simplification itself (MOA) so i have to backtrack you through.

Forget the height and width, that complicates things further. Start with the concept of length, denoting distance. Length of mildots, can only be understood after u grasp the basic of the standard of measurement (ie: Length). For this we use trigonometry and the radian measurement system.

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Minutes of Angle refers to a ratio of measurement. For this we need a standard of measurement: radian system. A radian can be translated simply as a "length" of some sort.

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Now in radians we have:

Degrees that can be split up in minutes

and these into seconds. They take up a radian length measurement in milimetres which i will cover ahead.

For Basics:

Start with a circle. The clock metaphor is useful to grasp the concept.

A circle has 360ÅŸ. This is 2pi radian. 1 radian is the "length" a circle. 1pi is the diameter too.

Of course here i have to watch out so u dont get confused... i mean length within a circle... which involves its rotation of course. Therefore 2 distict items,

1st: radian=the rotation itself

and 2nd: radius=the length from origin (centre).

So u have to make 2 radians (2pi) for a full circle, so 2 rotations of that radius or that "slice of the pie". Ok, that should do it.

For a shooter, you are the centre of the clock,... So direction, distance and many other things can be calculated from here like position, time of day etc. "Time" for example, is only another measurement of length. Relative to something of course, and here we have a standard.

Degrees can be converted in time measurements, and vice-versa.

1ÅŸ=60min

Minutes spit into seconds.

360ÅŸ in a circle... x60 min.

1 min is 1/60th of a degree. etc.

Here a radian system of measurement is used. For example: a small target (1 inch) at 100m. If u make a series of shots and it hits within, the rifle is said to shoot 1MOA. If it is a 2 inch at 100, it is said to fire 2MOA. If its 2inch at 200m it is said to fire 1MOA again. Or if its .5 inch at 100 it is said to fire 1/2 MOA, .5 at 200 a 1/4 MOA and so on.

So this refers to accuracy in relation to range. There r several factors that can alter accuracy (and range, eg: wind, gravity etc). But lets concentrate on only the 1st factor, accuracy. For this we look at the 3 elements.

1-barrel (or simply the weapon unit)

2-ammunition

3-human element (we will leave this out for simplicity sake)

A particular rifle can have a different bullet velocity depending on the class grade of ammunition used (even rifles within the same mk, and ammunition used. Weight of ammunition is needed, because it will be affected by gravity. For simplicity, trained marksmen select always a batch of the same grade ammunition. Made by the same manufacturer, on the same day, of the same batch (production methods can alter minute changes that make huge differences) so this variable can be kept relatively constant. We work within limits of an exact science, so bear with me.

Stats that r available everywhere are average calculations within the same class of weapon of the same mk - which is important to understand in accuracy shooting, small details count). This means it also refers to velocity of bullet. The deferential of this can be dependant on minor anomalies on manufacture, weight of grain (gun powder pellets) or any other that can alter, speed and velocity.

The basis of calculating MOA is trigonometry, which is the basis of ballistics. Therefore we try to measure the angle, the minutes of the angle... to a target.

So u have to take into account the vertical angle of deflection (MOA) or in other words its "bullet drop", so u can actually hit where u want to hit.

So a tangent of deflection (the curvature of the bullet path) is the effect in relation to the origin of the shot (where u r) and where the bullet drops.

Here u must understand the effects of gravity, and the "time" that a bullet is subject to that friction. Hehe... here we have "minutes of angle" , or "length of a variable (be it time, distance or whatever) that a bullet is subject to a deflection of its vector". It curves, so tangents are used! Put a straight line, that is the vector. In reality, gravity pulls it down, so it doesnt go in a straight line, it curves, so its vector changes.

It also affects its velocity, and acceleration. These variables are also in relation to "time".

MOA can be held with a simple thought of mind:

(range vs drop ratio) or simply its accuracy at a range.

A simple equation is:

(tangent angle) x (true distance to the target) = distance subtended

Of course this is more complicated, in relation to the weapon and ammunition used too - which every individual item can affect a distinct bullet drop. But for simplicity terms, rifle and ammunition would have to be tested before setting the MOA to that particular weapon in conjunction with the ammo used.

That is why u make a cold barrel shot for fine tuning... of that individual barrel. Its like getting to know its particular characteristic individuality. Every rifle is different, no matter how similar they may look like. This is a eternal truth for this fine craftsmanship. We work in detail, not in mass.

As for Mil dots, (markings in scope) same principle and measurement system base. Mil dots refer to miliradian measurement. It serves as a optical visual aid for calculating MOA but this gets into optics, more trig, which i aint going to discuss for here for now. But for simplicity sake, you have to know what distance (length) from centre reticule r the mildots. Remember what i told u about point of view, well this is exactly what i mean, the "lengths" to look out for r in relation to the scope itself, the length of each mil dot, the length between each, etc. These r visual aids to your true vector... the target view.

So u can convert to degrees, and go from there. So it might depend on a particular scope group markings. The standard of measurement of 1Mil is 3.60 degrees at 100m. Or in other words 1 miliradian is .36 at 100m.

Easily to get confused if not read carefully. So take your time.

[USSoldier11B 0]

Your explaination is too math geeky. You thought mine would be hard to understand? I got yours, but it put me to sleep. Just plain old 1 moa= 1 inch @ 100 m works ok, it's not like you are trying to hit a target 10 miles away.

This is why mathematicians aren't snipers. The war would be over by the time they calculated thier shots. Mil dots are used for QUICK range finding. You're not trying to hit a mosquito's dick.

[Ex-RoNiN 0]

Silly question, but do snipers and marksmen carry a calculator around to calculate all these adjustments? Or is it just educated guessing?

[scout 0]

usually targets move too fast for this kind of calculation.

thats why u train alot, so u could do it with a relative ease.

[USSoldier11B 0]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Silly question, but do snipers and marksmen carry a calculator around to calculate all these adjustments? Or is it just educated guessing?<span id='postcolor'>

It's actually not uncommon. That, or they will have all of the data predetermined on a laminated table. You use mil dots enough that you get to the point where you can do it in your head.

[Aculaud 0]

incredible...........thanks, everyone

[USSoldier11B 0]

Glad to help.

[Aculaud 0]

..................................................I can shoot 0 MOA in OFP

[DodgeME 0]

Hmmm isn't there a scope or a really high tech sniper rifle that calculates all that stuff but a CPU inside it and then output the info to the sniper. That would be sweat.

[theavonlady 2]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (DodgeME @ April 07 2002,14:59)</td></tr><tr><td id="QUOTE">Hmmm isn't there a scope or a really high tech sniper rifle that calculates all that stuff but a CPU inside it and then output the info to the sniper. That would be sweat.<span id='postcolor'>

Something like this?

[ran 0]

lol FCS ..... like on the modern MBT's

[theavonlady 2]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (ran @ April 07 2002,15:16)</td></tr><tr><td id="QUOTE">lol FCS ..... like on the modern MBT's <span id='postcolor'>

Now you mean like this.

[ran 0]

i've already seen this system

isn't it mounted on MAG machine guns on the puma engineer vehicle and on some others tsahal vehicles ?

[ran 0]

but one thing has just came to my mind : the camera can be broken easily , can't it ?

[ran 0]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (theavonlady @ April 07 2002,14:17)</td></tr><tr><td id="QUOTE"></span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (ran @ April 07 2002,15:16)</td></tr><tr><td id="QUOTE">lol FCS ..... like on the modern MBT's <span id='postcolor'>

Now you mean like this.<span id='postcolor'>

yes like that but with the turret of the tank

the Fire Control System of a tank includes the identification systems , the aiming systems , the variuos calculators ... etc

again , i'm maybe wrong

[theavonlady 2]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (ran @ April 07 2002,15:24)</td></tr><tr><td id="QUOTE">but one thing has just came to my mind : the camera can be broken easily , can't it ?<span id='postcolor'>

From what I've seen here on the news,it looks like the camera well is bulletproof but I'm not certain. No matter what, it beats popping you head out of the hatch!

[theavonlady 2]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (ran @ April 07 2002,15:22)</td></tr><tr><td id="QUOTE">isn't it mounted on MAG machine guns on the puma engineer vehicle and on some others tsahal vehicles ?<span id='postcolor'>

I've seen it on MBTs - possibly Merkavas but not sure.

[ran 0]

lol , right

in combat situation , i'd prefer to look outside trough a camera instead of opening my hatch , especially in urban operations