Win 300 Mag

[jcardona1]

Long range shooting fascinates me. Most people dont understand but a shot over 300 yards is pretty difficult. A shot at 600 yards, you REALLY have to know what you are doing and at 1,000 yards, you literally have to be a mathematician to get the round on target.

definitely. i always laugh at the guys that say then can take out deer at 300+ yds shooting free hand. most people have NO CLUE how difficult it is to shoot at that range, or theyre confusing 300yds with 300ft

 

[Liam]

Quick question, your rifle shoots 1MOA. Your scope has 1/4MOA adjustments. At 300 meter the bullet drops 1.5" How many clicks and what direction would you adjust your elevation? Bonus: what should you expect your 5-shot grouping be?


This is for Liam only and yes this is a VERY BASIC oh and EASY shot and calculation so Im sure he knows...

You don't think it's easy to hit a target and get a reasonable grouping at 300 yards? man what's your beef?

 

[JD7.62]

The answer was kind of a trick question because a rifle shooting 1MOA will have groups about 3" at that distance. With only 1.5" bullet drop, which is smaller then the rifle is capable of shooting, you wouldnt need to adjust your scope.

But if you wanted to bring the group up 1.5" youd have to adjust your elevation up two clicks. At 300m one click = 1/4MOA = 3/4" so two clicks = .5MOA = 1.5"

 

[akskirmish]

The answer was kind of a trick question because a rifle shooting 1MOA will have groups about 3" at that distance. With only 1.5" bullet drop, which is smaller then the rifle is capable of shooting, you wouldnt need to adjust your scope.

But if you wanted to bring the group up 1.5" youd have to adjust your elevation up two clicks. At 300m one click = 1/4MOA = 3/4" so two clicks = .5MOA = 1.5"

Talk english MF'er....LOL

Sad part-I know nothing of this part/aspect of things yet.......That was all foriegn as far as I am concerned...

Got a good link to where I can learn this type stuff......It's a must now..

 

[JD7.62]

Most firearm sighting scopes incorporate windage and elevation adjustments referenced to MOA (minute of angle). Each click of the scope turret is usually 1/4 MOA change and on some scopes 1/8 MOA. Normally, shooters refer to these adjustments as a change of a fraction of an inch at 100 yards rather than the true value of MOA for which they are supposedly calibrated to. The value of inch is a nice easy number to work with and most of us can easily visualize its length and its multiples without the aid of a calculator. Actually the comparison is close enough to not be of practical concern, especially at distances up to a few hundred yards, and the real difference is a mere 0.47 inch at 1000 yards. For serious target shooting and as shooting distances increase the attention to MOA value relative to sight adjustment becomes more essential.


Calculating Minute of Angle
The angle of an arc is expressed in number of degrees. There are 360 degrees of arc to a full circle. Each degree consists of 60 minutes of arc. The distance covered by the measure of arc is relative to the circumference (total distance around the circle) it is contained within. Knowing the radius (distance to center of circle) circumference is easily calculated by using the constant pi . The ratio (represented by pi ) of circumference is constant to diameter (radius x 2) regardless of circle size. The precise value of pi is so far unknown to man but is normally resolved to 3.1416 or 3.141 for our purposes.

Suppose a circle with a 6 inch radius. Circumference can be calculated as:

circumference = (radius x 2) x pi
circumference = (6 x 2) x 3.1416
circumference = 12 x 3.1416
circumference = 37.6992 inches

The distance covered by 1 degree of angle (37.6992 / 360 or, circumference divided by 360 degrees) is 0.1047 inch at 6 inches from center of circle.
And, 1 minute of angle represents (0.1047 / 60 or, 1 degree divided by 60 minutes) 0.001745 inch at 6 inches from center of circle.

Knowing what MOA represents allows us to calculate its value to any distance.
Six inches (the radius of the above example) is 1/600th of 100 yards: (100 yards x 36 inches) / 6 inches = 600
Therefore, the value of MOA at 100 yards is 1.047 inches (0.001745 x 600 = 1.047)
At 50 yards 1/2 the 100 yard value; 70% @ 70 yards; twice @ 200 yards; 6 times @ 600 yards; and so on.
So, the difference between thinking in inches as opposed to MOA is 0.47 inch @ 1000 yards.




Four (4) clicks of the scope adjustment equals 1.047 inch change @ 100 yards for scopes of 1/4MOA per click.


Where group size is expressed in inches the word 'inch' should be spelled. Writing the symbol commonly used to represent the measure of inch (") is not accurate here, and in fact misleading since that symbol also represents 'second of angle' (1/60 of a minute of angle). Therefore, a group of 1 inch would properly be written as '1 inch' not 1". It could also be written as 1' since that symbol (') is used to represent minute of angle but that might be misleading to those thinking in feet.


Why Use MOA
As shown above, the value of a measure of angle can easily be calculated to any distance from its source of origin - center of circle or muzzle of barrel. Such measures as MOA (minute of angle) are also part of our only universal language - mathematics. While knowing a rifle has a precision of a certain value of the inch at a particular distance also makes it simple to calculate its precision at other distances, one would have to know both the distance and the measure in inch (example: 1 inch @ 100 yards) before calculating it to other distances. In contrast, knowing only the measure of angle is needed to do the same. An example of the contrast is expressing 0.73 inch @ 100 yards verses 0.7 MOA (0.73 / 1.0472 = 0.697). The two equate practically the same (1 MOA = 1.047 inch @ 100 yards) but the expression using MOA is more concise since no distances are included in the expression.

Two informative sites for further discussion of MOA relative to firearm use: What Is MOA and Is It Really an Inch At 100 Yards? and Mil-dots and Minutes-of-angle, From a Technical Perspective


Calculating Scope Click
For long ranges where shooting distances may vary considerably it is wise to know the actual value of each scope adjustment. This is especially true if scope settings are changed in the field as shooting distances change. Not all scopes are precisely calibrated to MOA (minute of angle) or to the inch. Below is a procedure learned from Varmint Al's Shooting Page for better determining the value of each click of the scope turret.

Shooting from a solid bench rest, determine the center of group using the Average Group Radius method. Without reaching the adjustment limit of the scope, make and record as many scope elevation clicks as will still keep the group on the target while shooting at the same aiming point as before. Again determine center of group using the Average Group Radius method. Return the scope elevation to its previous setting. Determine the distance between the center of the two groups. Divide that distance by the number of elevation clicks used to achieve group two. That is the calculated value of change for that distance for each click.

For high power rifles it is recommended the target be no less than 100 yards distance as some projectiles may not completely stabilize at shorter distances, thereby giving a false indication of true performance.

In even simpler terms 1MOA is about 1" at 100m. So 1MOA at 200m is 2", and 3" and 300m. If your rifle shoots 2MOA its 2" groups at 100m, 4" groups at 200m, and 6" groups at 300m.

Does that make sense?

Like the article states, 1" doesnt equal exactly 1MOA but rather 1.047" but that is such a small difference that at 1000m its less then half an inch off. Of course at 1,000m there are so many variable that that half an inch is negligible of a difference.

Another good tip, is to learn what the size of the things are so you can get a decently accurate measurement of distance for your target. For example and Im going to use simple math here...

Your target is standing in a door way. You know the average door is 40" wide. By using your scope which will have some sort of way to measure MOA it appears your door is 10MOA wide. 40/10=4. Since we know that a MOA is about an inch we know that by doing the calculation of 40/10=4 we can figure the distance is 400m. To prove this, 1MOA at 400m is 4 inches. 4 inches x 10MOA (which we used our scope to get) equals 40 inches which we know is the width of your average doorway.

This is all regarding elevation and distance for for your target. Windage is a whole different ball game. Things that will have an impact on windage will be wind and the rotation of the Earth (yes for long shots around 1000m the rotation of the Earth comes into play).

However there are also other variables that effect elevation such as temperature, humidity, and angle to target. With a modern computer program or mobile device app, you can load your ballistic data as well as all of these variables (distance, wind, angle of shot, temperature, humidity, etc) and the program will do the calculations for you and direct you how to adjust your scope.

When you get an idea of how complicated this is, you get a GREAT respect for the worlds greatest snipers. Imagine doing all that in your head!!