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Author Topic: Inches, Minutes, and Clicks (IMC) - MOA and Sighting In  (Read 961 times)

Offline GunLink

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Inches, Minutes, and Clicks (IMC) - MOA and Sighting In
« on: October 07, 2015, 09:41:00 AM »
We've all seen (or maybe even been) the rifle shooter at the range wasting ammo trying to "walk in" their shots by making guesswork adjustments to the sights or optics.  It doesn't have to be that way.  If you know at what distance you are shooting and you are on paper, you can get your sights dialed in quickly and get on with your shooting enjoyment instead of being frustrated with your firearm and sights. 

Having a better understanding of how your sights (and bullet trajectories) work will not only let you spend more of your day making shots in the ten ring, it will make you a better shooter overall and allow you to be more adaptable - such as making adjustments for distance or environmental changes.

Here is an outstanding writeup about making sighting adjustments that we saw posted by our friends from Project Appeleseed of KY.  They talk about IMC:  inches, minutes and clicks.  If you know at what distance you are shooting and how far off your point of impact (POI) is from your point of aim (POA), then you can figure out how many minutes of arc (MOA) your shots are off by.  With that information, you can make the exact adjustments necessary to bring your POA and POI together, start getting hits on target, and stop using up all your ammo trying to zero your firearm.  Check it out... 

Inches, Minutes, and Clicks (IMC) are intimidating. But, the first step is simply remembering that 1 Minute of Angle (1 MOA) is very nearly the same as 1 Inch at 100 Yards. Remember this, and the rest is easy!

We all know this is an approximation, but it is a very good approximation. The value to 5 digits is 1.0472 inches, which is what 1 MOA is more precisely at 100 yards. But, the error in assuming that 1 Inch at 100 Yards is exactly the same as 1 MOA gives an error of less than half an inch even out at 1,000 yards! That is, the actual value at 1,000 yards would be 10.472 inches! Everyone can agree that being "off" by less than 1/2 inch at 1,000 yards is insignificant, when sighting in a rifle! So, if we simply assume that 1 MOA is the same as 1 Inch at 100 yards, we can scale the values at all other distances less than 1,000 yards with no appreciable error. The value at 100 yards is all that we have to remember!

Next, we must remember that angles do not exist at only one particular distance. As Buzz Light Year might say, to "infinity and beyond"! This is how we must think of angles. At longer distances, 1 MOA become larger distances than 1 inch. Therefore, at 200 yards, 1 MOA is 2 inches. At 300 yards, 1 MOA is 3 inches. And, at 400 yards, 1 MOA is 4 inches. And so on.
(keep reading...)

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Inches, Minutes, and Clicks (IMC) - MOA and Sighting In
« on: October 07, 2015, 09:41:00 AM »

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