what does 1/4MOA mean at 550 yards
- Thread starter DanK
- Start date
ronsroom1
Silver $$ Contributor
If you REALLY want to get Technical:
Minute-Of-Angle
The term "minute-of-angle",MOA) is used regularly by target shooters at the range, but is probably understood, thoroughly, by few,the same goes for mil-dots). Defined loosely, one MOA = 1" @ 100 yards; so, if you shot your rifle 5 times into a 100-yard target and every shot went into a one-inch circle you had drawn on the paper, then your rifle could be said to shoot 1 MOA. Likewise, if every shot goes into a two-inch circle at 200 yards, then you're shooting 1 MOA. A 10-inch group at 500 yards would be 2 MOA.
Now for the fun part. There are 360 degrees in a circle. Each degree can be broken down further into minutes. There are 60 minutes in a degree. Likewise, there are 60 seconds in a minute. Now, to figure out the distance subtended by 1 minute at any particular distance, we need merely to plug those two values into a simple trigonometric equation. The tangent function fits the bill nicely. Here's the equation:
tan,angle) = distance subtended/distance to the target,units must be consistent--e.g., 1/36 of a yard [1"] divided by 100 yards)
Now, we know the angle,1 minute or 1/60 of a degree) and we know the distance to the target,100 yards), but we need to figure out the actual distance subtended at the target,i.e., is 1 MOA actually 1" @ 100 yards?). What we need to do is solve for "distance subtended." Here's our final equation:
tan,angle)*distance to the target = distance subtended
Make sure your calculator is in "degree" mode,as opposed to "radian" or "gradian") and type in 1/60,for degrees) and hit the "tangent" button. Then multiply that by 100 yards. This should give you the distance,in yards) subtended at 100 yards. Multiply this by 36 to get inches. The answer should be:
1.047197580733"
This is just a hair over the commonly quoted "one inch." At 1000 yards, this would be almost 10 1/2 inches. Apparently, it is just a coincidence that 1 MOA happens to be REALLY close to 1" @ 100 yards. It is, however, quite convenient.
Minute-Of-Angle
The term "minute-of-angle",MOA) is used regularly by target shooters at the range, but is probably understood, thoroughly, by few,the same goes for mil-dots). Defined loosely, one MOA = 1" @ 100 yards; so, if you shot your rifle 5 times into a 100-yard target and every shot went into a one-inch circle you had drawn on the paper, then your rifle could be said to shoot 1 MOA. Likewise, if every shot goes into a two-inch circle at 200 yards, then you're shooting 1 MOA. A 10-inch group at 500 yards would be 2 MOA.
Now for the fun part. There are 360 degrees in a circle. Each degree can be broken down further into minutes. There are 60 minutes in a degree. Likewise, there are 60 seconds in a minute. Now, to figure out the distance subtended by 1 minute at any particular distance, we need merely to plug those two values into a simple trigonometric equation. The tangent function fits the bill nicely. Here's the equation:
tan,angle) = distance subtended/distance to the target,units must be consistent--e.g., 1/36 of a yard [1"] divided by 100 yards)
Now, we know the angle,1 minute or 1/60 of a degree) and we know the distance to the target,100 yards), but we need to figure out the actual distance subtended at the target,i.e., is 1 MOA actually 1" @ 100 yards?). What we need to do is solve for "distance subtended." Here's our final equation:
tan,angle)*distance to the target = distance subtended
Make sure your calculator is in "degree" mode,as opposed to "radian" or "gradian") and type in 1/60,for degrees) and hit the "tangent" button. Then multiply that by 100 yards. This should give you the distance,in yards) subtended at 100 yards. Multiply this by 36 to get inches. The answer should be:
1.047197580733"
This is just a hair over the commonly quoted "one inch." At 1000 yards, this would be almost 10 1/2 inches. Apparently, it is just a coincidence that 1 MOA happens to be REALLY close to 1" @ 100 yards. It is, however, quite convenient.
Since I’m a Simple Simon, I thought I’d figure out how this Minuet of Angle,MOA)stuff works in a less technical manor.
So how did I do it? Well what are the origins of a Minuet of Angle? The dictionary tells me it’s a circle. Okay, so if I am positioned at the bench and my target is 100 yards away and the MOA is about 1 inch from side to side; then I must be sitting in the middle of circle and 1 MOA must represents a measurement of 1 inch for the outside of that circle. That means 1 MOA is the outside measurement of a big slice of pie. Cool that’s easy.
There are 360 degrees in a circle and there are 60 minuets in a degree. Therefore, 360 times 60 equals 21600. There are 21600 slices in this big MOA pie. Okay lets brake this big pie down using the equation for the circumference of a circle. The equation for the circumference of a circle is pi,I use 3.141593) times diameter. My target is 100 yards away and I’m in the center so that means 100 yards is the radius. To get diameter you multiply the radius by 2; r2=d. But since my distances is in yards and my MOA is in inches I guess I have to convert something to inched; there are 36 inches in one yard.
So my equation to find 1 MOA at 100 yards should sound like this: 100yard radius times 2 to get the diameter times 3.141593,pi) times 36 to set the equation equal to inches all divide by 21600 pieces of the pie. This should yield the width of a 1 MOA slice of pie in inches. Here is the math: 100 x 2 x 3.141593 x 36 = 22619.4696 / 21600 = 1.0471976.
1MOA = 1.0471976inches at 100yards,
or 1.05in rounded off.
Here is a short cut to finding 1 MOA at any yardage. MOA means minuet of angle and d means the distance you are away from the target in yards:
1MOA = .010471976 x d.
Here is an example use JR’s fantastic shooting. He was 551 yards away from the target. So .010471976 x 551 = 5.77 inches. Therefore 5.77 inches equal 1MOA at 551yards. His groups were 1.23 and 1.91 inches respectively. So 5.77 divided by 1.23 equals 4.69 which to be generous is about 4 or one forth. One forth is a quarter. So a 1.23 inch group at 551 yards is a quarter-minuet group. 5.77 / 1.91 = 3.02inches or a third-minuet group.
Darn, that’s good shooting.
So how did I do it? Well what are the origins of a Minuet of Angle? The dictionary tells me it’s a circle. Okay, so if I am positioned at the bench and my target is 100 yards away and the MOA is about 1 inch from side to side; then I must be sitting in the middle of circle and 1 MOA must represents a measurement of 1 inch for the outside of that circle. That means 1 MOA is the outside measurement of a big slice of pie. Cool that’s easy.
There are 360 degrees in a circle and there are 60 minuets in a degree. Therefore, 360 times 60 equals 21600. There are 21600 slices in this big MOA pie. Okay lets brake this big pie down using the equation for the circumference of a circle. The equation for the circumference of a circle is pi,I use 3.141593) times diameter. My target is 100 yards away and I’m in the center so that means 100 yards is the radius. To get diameter you multiply the radius by 2; r2=d. But since my distances is in yards and my MOA is in inches I guess I have to convert something to inched; there are 36 inches in one yard.
So my equation to find 1 MOA at 100 yards should sound like this: 100yard radius times 2 to get the diameter times 3.141593,pi) times 36 to set the equation equal to inches all divide by 21600 pieces of the pie. This should yield the width of a 1 MOA slice of pie in inches. Here is the math: 100 x 2 x 3.141593 x 36 = 22619.4696 / 21600 = 1.0471976.
1MOA = 1.0471976inches at 100yards,
or 1.05in rounded off.
Here is a short cut to finding 1 MOA at any yardage. MOA means minuet of angle and d means the distance you are away from the target in yards:
1MOA = .010471976 x d.
Here is an example use JR’s fantastic shooting. He was 551 yards away from the target. So .010471976 x 551 = 5.77 inches. Therefore 5.77 inches equal 1MOA at 551yards. His groups were 1.23 and 1.91 inches respectively. So 5.77 divided by 1.23 equals 4.69 which to be generous is about 4 or one forth. One forth is a quarter. So a 1.23 inch group at 551 yards is a quarter-minuet group. 5.77 / 1.91 = 3.02inches or a third-minuet group.
Darn, that’s good shooting.
I calc the MOA of a 1.23" group at 551 yds as:
1.23 /,1.047197580733 * 5.51)
1.23 / 5.77005866983883
0.21316940959880335389120733785306
so a 1.23" group at 551 yds is a .213 MOA group,under a 1/4 MOA)
A 1/4 MOA is 5.77005866983883 / 4 = 1.443" approx. at 551 yds
VERY NICE SHOOTING JR!
551 yds, were did ya' come up with that one?
That's a strange yardage.
1.23 /,1.047197580733 * 5.51)
1.23 / 5.77005866983883
0.21316940959880335389120733785306
so a 1.23" group at 551 yds is a .213 MOA group,under a 1/4 MOA)
A 1/4 MOA is 5.77005866983883 / 4 = 1.443" approx. at 551 yds
VERY NICE SHOOTING JR!
551 yds, were did ya' come up with that one?
That's a strange yardage.
So now when nit picking starts at the range everyone can get their calculators and punch buttons until their eyeballs cross
For shooting purposes one MOA equals One inch at 100 yds. Any thing else just adds confusion. Like nautical miles, troy ounces, metric tons and such the MOA of one inch per 100 feet is accepted industry standard and so is what it is regardless of all the origins etc. Interesting discussion but doesn't change the standard. Keep her simple
For shooting purposes one MOA equals One inch at 100 yds. Any thing else just adds confusion. Like nautical miles, troy ounces, metric tons and such the MOA of one inch per 100 feet is accepted industry standard and so is what it is regardless of all the origins etc. Interesting discussion but doesn't change the standard. Keep her simple
Hi, My home range main prone mounds are in Meters but the 500met range actually measures at 551 yds,when i put in the 600 yd firing line we had all the good measure equipment so i measured the 500 met at the same time.. It's i think meant to be 547 yds but is a bit longer so i made the 600 one at 604 so no one could say we were cheating and it kind of evened things up.. 1000yd benchs are at 1004 also ..JR..Jeff Rogers.. ps targets are from the 500 Meter Benchrest FLY SHOOT events shot here in Australia.. the 5 targets shot in regestered comps go 1.23/ 1.62/1.63/1.68 and 1.91 ins respectivily,all shot with my rabbit gun
Kodiak99317 said:
BoydAllen
Gold $$ Contributor
Akbushape,
Says who, some gun writer? Units are what they are. Is is not the same as is approximately. I agree that for talking about wallet groups in the back of the gun shop close is good enough, but this is supposed to be an accuracy web site, and IMO that should include how things are measured, and how calculations are done. There is enough close is good enough in the rest of the shooting world. One more thing, in mathematics it is minute of arc, but I will use minute of angle as is customary in the shooting world. I can always tell when it is going to be colder weather than I like to go to the range in. I would never have wasted the bandwidth on this if I was getting ready to go to the range tomorrow. Have a happy healthy and prosperous New Year, and may all your groups be small ones.
Says who, some gun writer? Units are what they are. Is is not the same as is approximately. I agree that for talking about wallet groups in the back of the gun shop close is good enough, but this is supposed to be an accuracy web site, and IMO that should include how things are measured, and how calculations are done. There is enough close is good enough in the rest of the shooting world. One more thing, in mathematics it is minute of arc, but I will use minute of angle as is customary in the shooting world. I can always tell when it is going to be colder weather than I like to go to the range in. I would never have wasted the bandwidth on this if I was getting ready to go to the range tomorrow. Have a happy healthy and prosperous New Year, and may all your groups be small ones.
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.