Understanding Rifle Scope MOA

This is a great article that I found online about MOA:


MOA, or Minute of Angle, is a common measurement for describing various characteristics in rifle scopes. It is most generally used to illustrate the click value for windage and elevation turrets on rifle scopes. The click worth is how much the reticle moves per one click on the turret. Values from 1/8 to 1 MOA are generally experienced. For dot sights, MOA is usually used to describe the dot size and, within the instance of the circle-dot reticle, the circle size as well.



As a general rule of thumb, we say that 1 MOA equals 1 inch at 100 yards. By extension, that would be a couple of inches at 200 yards, 3 inches at 300 yards, etc. The smaller the click worth, the a lot more precise the windage and elevation modifications will be on your rifle scope. This precision could be essential during competitive shooting and for long-range shots. Furthermore, understanding the circle size in circle dot reticles helps make rifle scopes useful for rangefinding.


In our information of MOA, we'll start having a circle. Naturally, a circle is a geometric figure where all points are equidistant from a single point, known as the center. The distance from the center to the circle may be the radius and a segment of the entire circle is called an arc. The circle is divided into 360 degrees and every degree is divided into 60 minutes. Returning to our rifle scopes for a moment, one MOA is 1/60th of one degree.



For our illustration, we'll use a circle having a radius of one. Let's say it's one yard. If you paid attention in that geometry class, you'll remember that a circle with a radius of one is known as a Unit Circle. Utilizing a unit circle makes all the math easy. The circumference of the circle is decided by the formula, a couple of(pi)r, exactly where r is the radius and pi may be the constant worth 3.14. Pi is really one of those infinite decimals that keeps going on and on but we'll stop it at decimal a couple of points for our exercise.


So, our circumference is 2 times 3.14 times 1 or 6.28. Now we wish to determine the length of an arc determined by 1 MOA. So, 6.28/360 degrees is .0174 and we'll divide that by an additional 60 minutes to get .000291. Of course, we don't require rifle scopes to shoot anything one yard away, but we can calculate the length of an arc at 100 yards. To do so, we'll simply multiply the .000291 times 100 to get .0291. Easy math right? Now, to convert that to inches we'll multiply it by 36 since you can find 36 inches in a yard. So, .0291 * 36 = 1.0476


When peering through a rifle scope or red dot sight at a target 100 yards away, .0476 is a pretty insignificant amount so we merely rely on our rule of thumb that 1 MOA equals 1 inch at 100 yards.


Source: http://ezinearticles.com/?MOA-and-Adjusting-Your-Rifle-Scopes&id=3315444




 


Trijicon RX30 42mm Reflex Sight Amber 65 MOA Dot Reticle without mount
Trijicon RX30 42mm Reflex Sight Amber 65 MOA Dot Reticle without mount
$463.48
Time Remaining: 45m
Buy It Now for only: $463.48

Burris Fullfield II Riflescope 3 9x40 Ballistic Plex Matte 025 MOA BU200162
Burris Fullfield II Riflescope 3 9x40 Ballistic Plex Matte 025 MOA BU200162
$174.37
Time Remaining: 1h 8m
Buy It Now for only: $174.37

Night Force Scope Benchrest 12 42x56mm 125 MOA CH 2 C106
Night Force Scope Benchrest 12 42x56mm 125 MOA CH 2 C106
$1,400.00
Time Remaining: 1h 46m
Buy It Now for only: $1,400.00

115240 Leupold VX 3 Long Range 45 14x40 Riflescope Duplex Reticle 30mm 1 4 MOA
115240 Leupold VX 3 Long Range 45 14x40 Riflescope Duplex Reticle 30mm 1 4 MOA
$762.58
Time Remaining: 3h 27m
Buy It Now for only: $762.58

Sightron SII Big Sky 6 24x42mm Mil Dot Reticle Scope MOA Adjust Matte Black
Sightron SII Big Sky 6 24x42mm Mil Dot Reticle Scope MOA Adjust Matte Black
$580.00
Time Remaining: 5h 36m
Buy It Now for only: $580.00

63050 Sightron SII Big Sky Series 4 16x42 Riflescope HHR Reticle 1125 MOA Matt
63050 Sightron SII Big Sky Series 4 16x42 Riflescope HHR Reticle 1125 MOA Matt
$619.77
Time Remaining: 5h 49m
Buy It Now for only: $619.77

US Optics USOLR 17MOA 32 17X44 Lr 17 Moa Ret Fp Matte Black
US Optics USOLR 17MOA 32 17X44 Lr 17 Moa Ret Fp Matte Black
$3,125.11
Time Remaining: 5h 49m
Buy It Now for only: $3,125.11

300210 Burris 223 536 5X Prism Sight Illum Ballistic CQ 556 Reticle 33 MOA
300210 Burris 223 536 5X Prism Sight Illum Ballistic CQ 556 Reticle 33 MOA
$345.74
Time Remaining: 5h 49m
Buy It Now for only: $345.74

US Optics USOER 25MOA 5 25X58 Er 25 Moa Ret Ffp 34mm Matte Black
US Optics USOER 25MOA 5 25X58 Er 25 Moa Ret Ffp 34mm Matte Black
$3,754.59
Time Remaining: 5h 49m
Buy It Now for only: $3,754.59

7266 Konus KonusPro 4x32 Rimfire Scope Engraved 30 30 Reticle 1 Tube 1 4 MOA Ma
7266 Konus KonusPro 4x32 Rimfire Scope Engraved 30 30 Reticle 1 Tube 1 4 MOA Ma
$77.45
Time Remaining: 6h
Buy It Now for only: $77.45