What is MOA?

Ol' Timer · May 13, 2000, 12:27 AM

I know it stands for minute of angle, but what exactly does it mean? I've heard it used to describe the size of a dot on a red dot optic, and to describe accuracy in grouping, but I don't understand either one. Could someone please explain in very simplistic terms? Thank you.

Oh, while I'm asking questions in my very first post, why do some forums have crosshairs and others have bullet holes?

LawDog · May 13, 2000, 12:41 AM

Last question first:

The crosshairs mean that a post has been added since the last time you visited. Bulletholes mean no new post.

I'm a little rusty, but I believe that a minute of angle is roughly an inch at 100 yards. Thus a 2MOA dot would cover roughly a two-inch diameter circle on a target 100 yards away.

I think.

Welcome to the Firing Line.

LawDog

C.R.Sam · May 13, 2000, 12:45 AM

One minute of Angle tween two lines, the lines would be one inch apart at one hundred yards from the point of joining. A one minute dot would just cover a one inch spot at one hundred yards. If two shot holes are one inch apart and the target was one hundred yards away, the group is one minute of angle or a MOA group. One minute at two hundred yards = two inches. Thousand yards = ten inches etc.

------------------
Sam I am, grn egs n packin

Nikita Khrushchev predicted confidently in a speech in Bucharest, Rumania on June 19, 1962 that: " The United States will eventually fly the Communist Red Flag...the American people will hoist it themselves."

Ol' Timer · May 13, 2000, 12:45 AM

Thanks LawDog. Even I can understand that. And thanks for the welcome.

char923 · May 13, 2000, 12:47 AM

This is base on the amount of area covered at 100 yards. A ten MOA or ten-minutes of dot will cover approximately a ten-inch area at 100 yards.The dot appears to be constantly enlarging as the range increases, although it's actually still the same size, it's the change in perspective that creates this illusion.

houndawg · May 13, 2000, 01:17 AM

A minute is 1/21600 of a circle. There are 360 degrees in a circle, and 60 minutes in a degree. 360x60=21600. If the minutes stretched out 100 yards from the point of intersection, they would all be 1 inch apart from each other.

Big Bear · May 13, 2000, 01:55 AM

Just to add my $0.02 worth, at less than 100 yards, 1 MOA is less than 1 inch, i.e., at 25 yards, 1 MOA = 1/4 inch, at 50 yards, 1 MOA = 1/2 inch.

The 1 inch at 100 yards is approximate, but close enough for government work.

(Oh, BTW, I'm new around here too, but I didn't introduce myself, I just jumped in and started flapping my gums... err... keys. Welcome aboard, from one new member to another.

[This message has been edited by Big Bear (edited May 13, 2000).]

Jim V · May 13, 2000, 05:49 AM

Hey, welcome Ol' Timer and Big Bear. Nice to have you here.

------------------
Ne Conjuge Nobiscum
"If there be treachery, let there be jehad!"

Schmit · May 13, 2000, 06:07 AM

Ol Timer;

Here ya go http://www.sosmath.com/trig/Trig1/trig1/trig1.html

Now that that has you totally confused go here http://www.recguns.com/XIIC4.html

As you can see MOA are readily applied to shooting. However, their normal purpose is for global navigation. Latitude Longitude readings are put out in Degrees/Minutes/Seconds. http://www.geosys.com/cgi-bin/genobj...latlong/tig5e6

For example I live close to Greenville SC. Greenville is 34° 54' XX" North (34.54XXN) and 82° 13' XX" West (82.13XX) (I don't have the Lat/Long down to the seconds so I've represented those with XX). Always wondered about those little lines on maps/globes didn't ya?

Now you know The Rest of the Story It's really a "Squid" thing.

Oh, and BTW, welcome aboard.

------------------
Schmit
GySgt, USMC(Ret)
NRA Life, Lodge 1201-UOSSS
"Si vis Pacem Para Bellum"

[This message has been edited by Schmit (edited May 13, 2000).]

phonegunner · May 13, 2000, 12:01 PM

So then ... 1 MOA is = to 60 SOM ok....
Ted...

LawDog · May 13, 2000, 12:37 PM

Welcome aboard, Big Bear.

Schmit, I hate Lat/Long. Give me a decent MGRS grid co-ordinate any day.

LawDog

CS · May 13, 2000, 12:38 PM

> 1 MOA is = to 60 SOM <

Nope, I believe the correct phrase would be 1 MOA is = 60 SOA (60 seconds in a Minute, 60 Minutes in a Degree)

Which raises the point on another Law that can be passed! Shooters talk about 1/2 or . 5 Minute Groups.

They should instead say "I average about 30 - 45 Second groups with my rifle but today I shot a 10 Second of Angle one!!".

Looks like I'm going to have to pick up the gaunlet and become the Champion of Correct Angle Terminology! (much like some that Champion the proper use of Magizine (v Clip), .45 Colt (v Long Colt) and much to the confusion of everyone)

CS

[This message has been edited by CS (edited May 13, 2000).]

May 13, 2000, 12:27 AM	#1
Ol' Timer Junior Member Join Date: May 11, 2000 Posts: 11	I know it stands for minute of angle, but what exactly does it mean? I've heard it used to describe the size of a dot on a red dot optic, and to describe accuracy in grouping, but I don't understand either one. Could someone please explain in very simplistic terms? Thank you. Oh, while I'm asking questions in my very first post, why do some forums have crosshairs and others have bullet holes?

May 13, 2000, 12:41 AM	#2
LawDog Staff Emeritus Join Date: September 15, 1999 Location: Where am I going? Why am I in this handbasket? Posts: 4,194	Last question first: The crosshairs mean that a post has been added since the last time you visited. Bulletholes mean no new post. I'm a little rusty, but I believe that a minute of angle is roughly an inch at 100 yards. Thus a 2MOA dot would cover roughly a two-inch diameter circle on a target 100 yards away. I think. Welcome to the Firing Line. LawDog

May 13, 2000, 12:45 AM	#3
C.R.Sam Senior Member Join Date: October 29, 1999 Location: Dewey, AZ Posts: 12,858	One minute of Angle tween two lines, the lines would be one inch apart at one hundred yards from the point of joining. A one minute dot would just cover a one inch spot at one hundred yards. If two shot holes are one inch apart and the target was one hundred yards away, the group is one minute of angle or a MOA group. One minute at two hundred yards = two inches. Thousand yards = ten inches etc. ------------------ Sam I am, grn egs n packin Nikita Khrushchev predicted confidently in a speech in Bucharest, Rumania on June 19, 1962 that: " The United States will eventually fly the Communist Red Flag...the American people will hoist it themselves."

May 13, 2000, 12:47 AM	#5
char923 Senior Member Join Date: February 18, 2000 Location: Anchorage AK Posts: 237	This is base on the amount of area covered at 100 yards. A ten MOA or ten-minutes of dot will cover approximately a ten-inch area at 100 yards.The dot appears to be constantly enlarging as the range increases, although it's actually still the same size, it's the change in perspective that creates this illusion.

May 13, 2000, 01:17 AM	#6
houndawg Senior Member Join Date: February 8, 2000 Location: Illinois Posts: 479	A minute is 1/21600 of a circle. There are 360 degrees in a circle, and 60 minutes in a degree. 360x60=21600. If the minutes stretched out 100 yards from the point of intersection, they would all be 1 inch apart from each other.

May 13, 2000, 01:55 AM	#7
Big Bear Senior Member Join Date: May 9, 2000 Location: CA Posts: 120	Just to add my $0.02 worth, at less than 100 yards, 1 MOA is less than 1 inch, i.e., at 25 yards, 1 MOA = 1/4 inch, at 50 yards, 1 MOA = 1/2 inch. The 1 inch at 100 yards is approximate, but close enough for government work. (Oh, BTW, I'm new around here too, but I didn't introduce myself, I just jumped in and started flapping my gums... err... keys. Welcome aboard, from one new member to another. [This message has been edited by Big Bear (edited May 13, 2000).]

May 13, 2000, 05:49 AM	#8
Jim V Senior Member Join Date: January 31, 1999 Location: SE Michigan - USA Posts: 4,038	Hey, welcome Ol' Timer and Big Bear. Nice to have you here. ------------------ *Ne Conjuge Nobiscum* "If there be treachery, let there be jehad!"

May 13, 2000, 06:07 AM	#9
Schmit Staff Alumnus Join Date: March 11, 1999 Location: Masquito infested flatlands of Mid-FL Posts: 1,857	Ol Timer; Here ya go http://www.sosmath.com/trig/Trig1/trig1/trig1.html Now that that has you totally confused go here http://www.recguns.com/XIIC4.html As you can see MOA are readily applied to shooting. However, their normal purpose is for global navigation. Latitude Longitude readings are put out in Degrees/Minutes/Seconds. http://www.geosys.com/cgi-bin/genobj...latlong/tig5e6 For example I live close to Greenville SC. Greenville is 34° 54' XX" North (34.54XXN) and 82° 13' XX" West (82.13XX) (I don't have the Lat/Long down to the seconds so I've represented those with XX). Always wondered about those little lines on maps/globes didn't ya? Now you know The Rest of the Story It's really a "Squid" thing. Oh, and BTW, welcome aboard. ------------------ Schmit GySgt, USMC(Ret) NRA Life, Lodge 1201-UOSSS "Si vis Pacem Para Bellum" [This message has been edited by Schmit (edited May 13, 2000).]

May 13, 2000, 12:01 PM	#10
phonegunner Junior Member Join Date: May 12, 2000 Location: SLC,UT,USA Posts: 1	So then ... 1 MOA is = to 60 SOM ok.... Ted...

May 13, 2000, 12:37 PM	#11
LawDog Staff Emeritus Join Date: September 15, 1999 Location: Where am I going? Why am I in this handbasket? Posts: 4,194	Welcome aboard, Big Bear. Schmit, I hate Lat/Long. Give me a decent MGRS grid co-ordinate any day. LawDog

May 13, 2000, 12:38 PM	#12
CS Junior Member Join Date: May 4, 2000 Location: Washington DC Posts: 10	> 1 MOA is = to 60 SOM < Nope, I believe the correct phrase would be 1 MOA is = 60 SOA (60 seconds in a Minute, 60 Minutes in a Degree) Which raises the point on another Law that can be passed! Shooters talk about 1/2 or . 5 Minute Groups. They should instead say "I average about 30 - 45 Second groups with my rifle but today I shot a 10 Second of Angle one!!". Looks like I'm going to have to pick up the gaunlet and become the Champion of Correct Angle Terminology! (much like some that Champion the proper use of Magizine (v Clip), .45 Colt (v Long Colt) and much to the confusion of everyone) CS [This message has been edited by CS (edited May 13, 2000).]