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.
7260 Konus KonusPro 2 7x32mm Riflescope Engraved 30 30 Reticle 1 Tube 1 2 MOA M
Time Remaining: 31m
Buy It Now for only: $70.96
7249 Konus KonusPro 15 5x32mm Shotgun Scope Aim Pro Reticle 1 Tube 1 4 MOA Mat
Time Remaining: 31m
Buy It Now for only: $78.25
510479 Simmons ProSport 3 9x50 Riflescope Truplex Reticle 1 Tube 1 4 MOA Matte
Time Remaining: 33m
Buy It Now for only: $76.74
Sightron SII 3 9x42 Riflescope Duplex Reticle 125 MOA Matte Black SII39X42
Time Remaining: 1h 1m
Buy It Now for only: $220.54
853940B Bushnell Legend Ultra HD 3 9x40 Riflescope DAO 600 Reticle 1 4 MOA Matte
Time Remaining: 1h 2m
Buy It Now for only: $221.85
7234 Konus KonuShot 3 9x32mm Riflescope 30 30 Wire Reticle 1 Tube 1 4 MOA Matte
Time Remaining: 1h 3m
Buy It Now for only: $56.13
63014 Sightron SII Big Sky 4 16x42mm Riflescope Dot Reticle 1 1 8 MOA Adjustabl
Time Remaining: 1h 4m
Buy It Now for only: $564.99
63009 Sightron SII Big Sky 3 12x42mm Riflescope Plex Reticle 125 MOA Adjustmen
Time Remaining: 1h 19m
Buy It Now for only: $489.92
63050 Sightron SII Big Sky Series 4 16x42 Riflescope HHR Reticle 1125 MOA Matt
Time Remaining: 1h 20m
Buy It Now for only: $564.83
Bushnell ET1X32 Elite Tactical Red Dot Matte 1x32 3 MOA Dot Elite Tactical Red D
Time Remaining: 1h 31m
Buy It Now for only: $264.27