# What does MOA mean??

BBsteel

May 8, 2007, 10:24 AM

I pistol and shotgun shoot. I only own a .22 long rifle. Just wondering what is meant by 1/2 MOA, sub MOA, 1 MOA etc... I will purchasing a varmit rifle in the future but not anytime within the next 6 months. The .223 and .308 are both appealing to me and I'll eventually have both so I'll start with the .223.

Thanks for answering

If you enjoyed reading about "What does MOA mean??" here in TheHighRoad.org archive, you'll LOVE our community. Come join

TheHighRoad.org today for the full version!

sansone

May 8, 2007, 10:31 AM

moa= minute of angle. angles are measured in degrees and minutes. 1moa is 1" deflection @ 100yds, the confusing part is 1moa equates to 2"@200yds.

MIL-DOT

May 8, 2007, 10:40 AM

a couple years ago i could have quoted you chapter and verse on all that milliradian,minute-of-angle stuff, but.....:confused:

check out the sniper rifle forums, their FAQ pages will give you the low down in a fairly comprehendable manner. also great sites for the straight scoop on optics.

BBsteel

May 8, 2007, 10:43 AM

That is confusing. Does that mean that 1MOA equates to 3" @ 300 yards? Sounds like you need to establish the yardage when reporting MOA??

Mr White

May 8, 2007, 10:58 AM

Yes. Basically a good rule of thumb is that it is 1" for every hundred yards.

The math:

100 yd=3600"

At 100 yd from target, imagine a huge circle with you at the center and the target out at the edge.

Diameter of said circle is 200 yd which = 7200 inches. circumference is pi*diameter, or 7200*3.1416, or 22619.52 inches.

360 degrees in a circle. 22619.52/360=62.832 inches in 1 degree of that circle. 1 minute=1/60 of a degree, so one minute of that 62.832 inch degree would be 1.047 inches. Pretty close to an inch.

Like I said 1"/100 yds is an estimation. At 600 yd, 1 MOA equals 6.283", not an even 6", but close enough. You can use that math to figure MOA for any distance.

I hope that helped.

Medusa

May 8, 2007, 10:58 AM

MOA means minute of an angle, ie 1/60 degree, roughly it's 1 inch (1.045 more precisely) per each 100 yards, or 29 mm per 100 m. It shows the amount of dispersion of the rifle/ammo system. You can visualize it with the light, the lesser dispersion, the tighter the "beam" is.

Conversion factor is Tan(1/60), or 2.9e-4, or 0.00029. you multiply it with the distance to get the amount of dispersion.

sub moa means that the rifle/ammo combo puts bullets into the circle that is no bigger than 1 inch at 100 yards. All the fractional moas mean the same, for example DSR-1 is a 1/5 moa rifle, with equal ammo it means the group size will be 1/5 inch at 100 yards, basicly a ragged hole.

But be warned, accuracy at long range depends a lot from the ammo, if one rifle/ammo combo shoots 1 moa at 100 yards it doesn't mean it shoots 6 inch group at 600 yards.

For example I shot 10-15cm group at 300 m (330 yards), with Galil Sniper (7.62x51 cal), but at 557 m (610 yards) it was 35-45 cm.

Added: heh mr White, same time replying basicly same thing

BobTheTomato

May 8, 2007, 11:06 AM

I'm not sure if this will help clarify things but in surveying you measure angles in Degrees, minutes, and seconds. So a minute is 1/60 of a degree and a second is 1/60 of a minute. so in other words 30.016666666 degrees is:

30 deg 01 min 00 sec

So if we do the trig for 1 MOA at 100 yds.

Sin 1/60 = x / 100 yds

x = .0290888 yds

x = 1.047 inches at 100 yds

Then 200 yds is 2.094 in and so on

Edit: Oops Medusa and Mr white posted when I was writing

lionking

May 8, 2007, 11:12 AM

quote;sub moa means that the rifle/ammo combo puts bullets into the circle that is no bigger than 1 inch at 100 yards

thanks for breaking it down to simple terms for me.

hate to admit it but I was always confused about this and whenever someone posted "my rifle shoots sub-moa" I never really knew what that meant other than it "sounds accurate".

so lets say if a rifle produces a 2 inch group at 100yds how does that describe it in moa terms?

sectional_density

May 8, 2007, 11:25 AM

"so lets say if a rifle produces a 2 inch group at 100yds how does that describe it in moa terms?"

2 MOA.

Looks like people have already described the calcs pretty well. Another way to consider 1 MOA at 100 yards (1.047") at the tip of a 24" barrel, is that you have about .007" diameter of wiggle room to keep it 1 MOA at 100 yards. A bit harder to do in the field without benches and sandbags. Prone shots w/ bipods are sure nice though!

lionking

May 8, 2007, 11:45 AM

sectional....well duh me.:o I knew I would sound like a dummy asking this but I had to so I could finally understand this.Math was never a good subject for me.

BBsteel

May 8, 2007, 12:14 PM

Great responses, thanks much!! Well understood now.

SnakeEater

May 8, 2007, 01:05 PM

I wish a mod would sticky this thread. This question is asked frequently.

If you enjoyed reading about "What does MOA mean??" here in TheHighRoad.org archive, you'll LOVE our community. Come join

TheHighRoad.org today for the full version!

vBulletin® v3.8.6, Copyright ©2000-2016, Jelsoft Enterprises Ltd.