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Old August 10, 2002, 05:55 PM   #1
sweeper455
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minute of angle (moa)

can someone tell me exactly what moa is and what it looks like on paper?
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Old August 10, 2002, 06:05 PM   #2
Jorah Lavin
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Ahhh, I asked the same thing meself not too long ago

A quick search will bring up oodles of hits, I'm sure (the TFL search engine is your friend, no kidding)

Minute of angle is one tiny slice out of an imaginary compass, of which you are the center of the circle, and the horizon is an easy thing to use as the "edge."

If the circle had a diameter of 200 yards, then MOA will be roughly an inch wide, or an inch wide 100 yards away from you. 200 yards away, MOA would be roughly 2 inches, and so on.


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Old August 10, 2002, 06:27 PM   #3
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"A quick search will bring up oodles of hits, I'm sure ...

I'm positive.
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Old August 10, 2002, 06:28 PM   #4
WIL TERRY
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M O A is exactly[ give or take the odd furlong ]

1.047" at 100 yards. You can figure out all the rest from there.
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Old August 13, 2002, 03:28 AM   #5
Long Path
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The Moa was a large, flightless bird from New Zealand, which got up to 9 feet tall!

Oh, also a Minute Of Angle is an arc that subtends one sixtieth of one degree. As there are 360 degrees around you, there are thus 21,600 Minutes Of Angle around you. Thus a circle around you with a 100 yd radius would be 1884.6 feet around. My math checks with Wil Terry, inasmuch as, when computing M.O.A., you must realize that that the distance from you to the target is the radius of a large circle. At 100 yards, the diameter of that circle is 600 feet, or 7200 inches. Multiply that by 3.14159 (Pi), and you get 22608 inches, which, divided by 21,600 (# of Minutes in a circle), yields 1.0471966666...."

Close enough.
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Old August 14, 2002, 12:45 AM   #6
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Just today I had an odd thought long before seeing this thread:

Howcome those Benchrest shooters measure their groups in decimal inches (approximating MOA) instead of in angular SECONDS?

"That there's a 30-Second barrel all the way out to 600 yards!"

Sorta like George Carlin's observation about how nobody ever tries to look "chalant".
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Old August 14, 2002, 02:02 AM   #7
Steve Smith
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Because most Benchresters dont' shoot out to 600 yards.

(sarcasm)
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Old August 14, 2002, 12:58 PM   #8
Long Path
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You know-- I don't know? It would make sense, wouldn't it? Among a fraternity that loves to brag that their best groups fall between 0.05 and 0.25 MOA, wouldn't it be natural to just drop down one more space on the base 60 scale? Why mix base 10 with base 60? Rather than a .25 MOA group, guys could proclaim that they shot a 15 SOA group, and be utterly clear in their terminology.

Likewise, Cheapo, why does the dictionary disallow me from proving that I am "ept"?
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Old August 14, 2002, 04:54 PM   #9
labgrade
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I'm still trying to buy parel capers in the grocery store- nowhere top be found.

Sheesh. Ask what time it is & youse guys ...

Jorah,

1" at 100 yards is close enough for anything practical. All the explanations are on the money. 1 MOA = 1" at 100, 2" at 200, & so on.

BR guys do the decimal inches measuring bit 'cause it's more accurate than MOA-anything. & really, who cares? One unit of measuring is just as good as another long as you have "honest weights & measures."
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Old August 14, 2002, 05:03 PM   #10
Mal H
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Quote:
... trying to buy parel capers in the grocery store ...
I know there's a joke in there somewhere labgrade, but dang me if I get it. Please 'splain it to me 'cause I've pondered on it too long now.
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Old August 14, 2002, 05:17 PM   #11
labgrade
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Mal, just referencing the rest of the non-things ... as in a nonparel caper ... ?

& I haven't a clue what any kinda caper is. Some food-stuff-thing/spicey-dealy .... other than seeing the darned bottles on the shelf, only time I've ever heard of 'em is in The Invasion of the Body Snatchers (last run - Brooke Adams = yum ) .....

Hows that for thread drift?
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Old August 14, 2002, 11:33 PM   #12
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I hired Tom because he was kempt and ept.

Base six pretty natural for me from getting celestial nav etc hammered into my skul.

Hooter is we used to measure our groups with outside distance instead of center to center. I think it was the benchresters that first started using center to center. ½ inch goup sounds better than 3/4 " group any day.......even tho it was the same group on the same target fired with a .25 caliber.

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Old August 15, 2002, 12:26 AM   #13
Long Path
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Yep. That's some serious thread drift, bud.

That's actually nonpareil. Nonpareil capers are so named, I think, because they resemble the candy: Merriam Webster gives a couple of definitions for the noun form of this word:
Quote:
Main Entry: 2 nonpareil
Function: noun
Date: 1593
1 : an individual of unequaled excellence : PARAGON
2 a : a small flat disk of chocolate covered with white sugar pellets
b :sugar in small pellets of various colors
I measure groups from the outside of one extreme hole to the inside of the furthest hole from it, which gives me center to center groups, or the group minus the caliber. This became necessary to satisfy the strains on my ego.
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Old August 15, 2002, 12:40 AM   #14
Frohickey
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MOA... Minute of Angle.
Circle has 360 degrees... each degree is 60 minutes.

Tangent of 1/60th of a degree is 0.0029088903.
Multiply that by 100yards comes out to 1.0472 inches
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Old August 15, 2002, 06:46 AM   #15
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Ah, I see, labgrade! I am now plused. But, spelling man! Spelling is essential for word gags!

[parallel capers? no
a pair of cappers? no
I just couldn't figure it out.]
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Old August 15, 2002, 09:29 AM   #16
C.R.Sam
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Yeah Mal...
"Gord Wags" is a bit unfinitive.

Sam
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Old August 15, 2002, 10:20 AM   #17
moredes
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MOA = Minute Of Angle (rather than go into a long explanation, accept for right now that a MOA is X inches, [a spacial measurement used in target resolution] derived at any distance; it is the result of dividing a distance [measured in yards} by 100. Therefore, if your object distance is 150 yards, 1 MOA is 1.5", at 200yd it's 2", at 300yd it's 3", at 900yd it's 9". If I say my rifle is capable of 1/2 MOA accuracy, it means I can shoot 5 shots in a group no bigger than half the inches I've given above at those distances.)

MOA measurement is an important feature when viewing a target through a mildot reticle. They are subtended by dots usually spaced 1 MOA apart. This configuration is generally good only at certain scope magnifications (except for Generation II scopes, where the mildot reticle's MOA values are valid at any magnification).
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Old August 15, 2002, 10:58 AM   #18
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Actually, mildot scopes are different, and use one mil as a unit of angle measurement instead of minute of angle.

Mildot explained

One mil is one milli-radian. There is 3.1415926 radians in 180 degrees. One milli-radian is 0.05729 degrees.

Tangent of 0.05729 is 0.00099989946.
Multiply that by 100 yards comes out to 3.5996 inches.

For comparison, one MOA is 0.0166667 degrees, while one milliradian is 0.05729 degrees.
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Old August 15, 2002, 07:49 PM   #19
moredes
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Oops! brain fart. Frohickey's right, of course. Shows how often I mil at unknown distances.
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