#riflescopeforhunting #shooting #riflescopes
Go to here for a more simplified MOA explanation: • Minute-Of-Angle (MOA) ...
If your new to the MOA system, I suggest reading the description in addition to watching the video.
What does the term Minute of Angle (MOA) mean to a shooter using a riflescope or a spotter calling out information to the shooter?
Like everything in this world we need to build a good educational foundation to understand things. Let's begin.
First, the term "Minute of Angle" is a form of angular measurement used extensively in the firearm industry to communicate similar knowledge or information between shooters for the purposes of;
1) What type of riflescope reticle system shooters use. (As opposed to an MRAD riflescope system.)
2) MOA also communicates between shooters their elevation and windage adjustments to make or made to help zero the rifle's aim point on target.
3) How to make elevation adjustments for calculating "bullet drop".
A simple explanation for MOA is: one MOA is 1 inch at 100 yards, 2 inches at 200 yards, 3 inches at 300, etc,. Do you see a pattern here? But, how did I get these numbers? I show you in this video.
Moving forward a "Minute of Angle" (MOA) is again a form of angular measurement that uses "degrees". Now, you might be asking yourself, "so Tim, what do degrees have to do with MOA?"
It has everything to do with MOA!
To help understand shooter's Minute of Angle, using a circle and degrees, I want you to picture in your mind a full circle with the shooter always at the center (vertex) of the circle. A fully enclosed circle from end-to-end has 360 degrees of "arc". As a shooter, we are only focused on what's occurring within "one sixtieth of one degree" of that 360 degree circle. This "1/60th of one degree" is known as the "Minute" in the term "Minute of Angle" used in the firearm industry. It is also known as the "arcminute" in other scientific disciplines. Therefore, in a full circle there are 21,600 minutes of angle. This is calculated by multiplying 360 degrees times 60 minutes which is 21,600 minutes of angle or arc.
To further help describe in simplistic terms "arcminute" or "minute" a bullet travels along a straight line (lets say along the "90 degree line") within a circle. The bullet's path involves a fractional proportion within that "one degree" of the circle's 360 degrees. In other words, it means that we are only using 1/60th of that one degree , or in mathematical terms - 1 divided by 60 (1/60) is 0.016667 (rounded) degrees. (We'll use this value later.)
Lets keep going! Now, draw a straight line from the center of the circle out to the circle's boundary. This line is known as the "radius. We'll use a radius of 100 yards. In our MOA explanation the radius is the length or distance from the center of the circle (shooter's position) to any point on the circle's boundary. For instance, the shooter might be shooting at a distance (radius) of 100, 200, 300, or 600 yards. However we also need to understand that when we shoot a bullet on planet Earth another factor comes into our equation - gravity. A bullet travels flat for a known distance, and as soon as gravity comes into play, we get the introduction of another important factor - known as angle. At 100 yards the "arc length" is the distance between 2 points on the circle's boundary or edge created by two lines (rays) that spread out further as the distance increases from the center of the circle ) which is calculated by using an equation (See this video for how?). The one degree angle (theta) will create an "length of arc" segment value on a circle's boundary that is used to calculate the precise minute of angle at 100 yards. The length of arc depends on the distance from the center of the circle to it's boundary. The length of arc increases as target distances are moved further out. In our discussion here we continue to use the distance of 100 yards. So the arc length at 100 yards is the angle's size ( 1 ) times (PI or 3.14159)/180) times distance (convert 100 yards to 3600 inches) which is 62.83 inches. So, 1/60th of the (1 degree) arc length at 100 yards is 62.83 inches. That is, at 100 yards, 1 MOA is calculated by: 62.83 x 0.016667 (1/60) which is 1.047 inches.
Shooter's round it off to 1 inch at 100 yards also called the "shooter's Minute of Angle (sMOA)." How did I get this calculation? Watch the full video.
As a shooter, understanding the fundamentals behind Minute of Angle gives a shooter the knowledge to advance their skills to the next level. It goes to say that a shooter becomes more confident when calculating clicks on a riflescope turret when adjusting for elevation, windage, and bullet drop. This knowledge also comes in handy when communicating with others within the firearm industry, purchasing a new riflescope, and talking with shooters at the range or in your group chats.
22 фев 2023
