MOA

knucklehead14

what does MOA stand for?
I Think it has something to do with group size but I`m not sure.
Thanks.

knucklehead14

If is 1" @ 100 yds., 2" @ 200 yds
What is it at 400 yds ?

knucklehead14

I think I have heard that in shooting "MOA" means, Minute of Angle.
Will one of you knowledgeable people please explain this term and why is it a better description of placed shots than used years ago. Also how long has it been in use. Please be specific with your replies as I wish to print out the replies for keeping. Thanks

Dr. J. Curtis Lane

redcedars

minute of angle

1/60th of one degree, 1" at 100 yards

A "one minute" gun is capable of 1" groups at 100 yards.

redcedars

nononsense

knucklehead14,

I know that this will sound like nitpicking and it is but Minute of Angle at 100 yards is equal to 1.0472" not just one inch. Use this link for one of the easiest explanations that I've read.

http://www.aeroballisticsonline.com/ballistics/minuteofangle.html

I'm not being critical of redcedars at all since most of the time we all think of MOA as being 1 inch at 100 yards, it's faster and simpler. But, when it comes to measuring groups in any form of competition, accuracy of measurements is paramount.

Best.

gskyhawk

you could add that a sub MOA gun will hold its group at what ever the range is ie
1 inch or less at 100 yards
2 inches or less at 2oo yards
3 inches or less at 300 yards
for the average person / hunter MOA is 1 inch at 100 yards
they may get down to the thousands of inch in bench rest compettions but for the average Joe going out to see what is rifle can do 1 inch is fine
Not taking any thing away from nononsense( whos right ) just saying most people don't get that picky[:D]

Travis Hallam

Another point to bring up is that the "average joe" groups are measured from the center of the bullet holes and not the outside diameters. In competition I imagine they take the ouside diameters and subtract the bullet diameter. That is how you get groups that are .01 MOA (or less).

Mad Dog

easygo6

Thanks Travis,

I appreciate learning something knew tonight!

SEMPER FI

nononsense

There are as many explanations as to how a target gets measured as there are targets and shooters. Here are a couple of responses regarding match target measuring that I copied from a benchrest site.

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"At benchrest matches, groups are measured under magnification, using a caliper-mounted reticle plate with a scribed circle. Centering this circle on the bullet holes largely eliminates problems with trying to find the edge of the hole, and the resulting center-to-center group measurements are pretty accurate."

"Still, the caliper's ability to measure in 0.001" increments does not mean measurements are correct to 0.001". Actual precision of group measurements is probably on the order of plus or minus 0.005" (five thousandths), and remeasurement by a different scorer or under different lighting conditions will often if not usually result in a slightly different group size."

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"...when groups are measured at matches, the scorer only reads the instrument in .001 increments. The computer, when averaging the data, converts to four places, or tenths. For example, a combined agg of .232, .197, .282, .205, .221 would add up to 1.137, divided by five for an agg of .2274."

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Just for the sake of information and discussion.

Best.