struggling with moa

[nearly there]

Hi Is there any websites that can explain moa in basic terms.I'm looking to work out how much to dial up from a 100 yrs zero.I'm sue this is basic stuff but I struggle with the calculations.thanks

[HALODIN]

I use the iStrelok ballistic calculator for my boing, it's really simple. See if your scope's in this list. He's really friendly, if it doesn't cover your scope he'll probably add it.

http://istrelok.borisov.mobi/

[kevinww]

1 moa is approx 1 inch per 100yds so 1moa is

1 inch at 100yds
2 inches at 200yds
3 inches at 300yds
4 inches at 400yds
etc

so if your scope is 4 clicks per moa

1 click will shift POI

0.25" at 100
0.5" at 200
0.75" at 300
1" at 400
etc

[WelshShooter]

You need to know two things. One, the velocity of your ammunition and two, the amount of MOA adjustment required at a certain distance. Most factory ammunition will have published velocities (might even be on the box) and then you'll need a ballistic calculator. Hornady have a good one. Just complete the basic table and you can have it produce a simple table telling you "if at distance X yards then adjust elevation by Y moa."

Hope this helps!

[nearly there]

Thanks guys

[Maggot]

Once you have a start point, regularly note the ACTUAL values for each range (Either by clicks from zero if the scope does not have good verniers or via the vernier reading on the turret).

You can log these on a plot sheet or a turn of tape round the small of the but or the eyebell

I remember seeing a basic rule of thumb for .308 which went something like

0-1 1MOA

1-2 1MOA

2-3 2MOA

3-4 2MOA

4-5 3MOA

5-6 3MOA

6-7 4MOA

7-8 4MOA

8-9 5MOA

9-10 5MOA....The thing is I cant remember whether it started at 2 or 1....


but it goes 11 22 33 44 55 might go 22 33 44 55 66.....when I looked at my actual come ups it was pretty close.

It was an American thing but I am damned if I remember where I saw it. Sorry

[phaedra1106]

This explains it pretty well,

https://www.youtube.com/watch?v=VA2PZBD ... re=related

[TattooedGun]

Once you have a start point, regularly note the ACTUAL values for each range (Either by clicks from zero if the scope does not have good verniers or via the vernier reading on the turret).

You can log these on a plot sheet or a turn of tape round the small of the but or the eyebell

I remember seeing a basic rule of thumb for .308 which went something like

0-1 1MOA

1-2 1MOA

2-3 2MOA

3-4 2MOA

4-5 3MOA

5-6 3MOA

6-7 4MOA

7-8 4MOA

8-9 5MOA

9-10 5MOA....The thing is I cant remember whether it started at 2 or 1....


but it goes 11 22 33 44 55 might go 22 33 44 55 66.....when I looked at my actual come ups it was pretty close.

It was an American thing but I am damned if I remember where I saw it. Sorry

I think this is more detrimental to someone asking how it works in simple terms than any other message I've ever read? What the hell are you even talking about?

[WelshShooter]

(...)

I think this is more detrimental to someone asking how it works in simple terms than any other message I've ever read? What the hell are you even talking about?

Phew, I'm glad I wasn't the only one

[Laurie]

Strictly speaking, the MOA is a part of one degree of the 360-degrees in a circle. Google it and you'll see the exact definition easily enough. Use of MOA was adopted by shooters and artillerymen amongst others as a way of easily setting or resetting sights / aim. The 1-inch at 100 yards and equivalent for longer distances isn't too far out and is fine for short distance use. In actual fact, the exact amount is 1.047" per 100 yards, which starts to make a difference at 1,000 (ie 10 x 100) yards when it's nearly 10 1/2 inches (10.47") rather than 10.

Why use MOA instead of inches? Think about changing from a 100 yard scope zero to shooting at a target 1,000 yards away. You have the MV for the load, you have the BC (ballistic coefficient) for the bullet. Feed them into a ballistics program and it gives the bullet drop over that distance with this zero setting, which becomes the 'come-up' needed on the sights. Saying the strike is predicted to be 366 inches low if the sight setting is left unchanged isn't really helpful. That's 35-MOA though, and on an MOA calibrated scope, it's an easy and relatively foolproof way of making the adjustment change. On the Sightron Series III target scopes I use, there are 15-MOA per full turret rotation, so I would turn the elevation turret through three full turns from the 100 yard setting, then go 'up' another 5-MOA. This and many such modern scopes use large externally marked turrets showing full MOA with a numbered large mark and intermediate smaller quarter-MOA hash marks.

For known distance prone deliberate shooting such as Target Rifle and F-Class, most competitors use an appropriate plotting sheet which places a correctly dimensioned target representation over a 1-MOA grid allowing easy calculation of both corrections and wind effects. The standard NRA TR ringed target which is what is most likely to be used in general target shooting on fullbore ranges has a 10.5" 'V Bull' (1-MOA); 21" 'Bull' (2-MOA), 42" 4-ring (4-MOA) for its centre in the 1,000 yard version. You take your first shot at it on your predicted setting and find you're high, level with the top of the 4-ring and way off to one side because of the wind conditions. The plotting sheet allows you to easily convert the error into an MOA change on the sights - say drop the elevation by 1 1/2-MOA or 6 clicks on most scopes or iron target sights (double that on models with 1/8-MOA adjustments) and move the windage by three or four MOA as determined by the grid on the sheet.

F-Class uses much smaller targets than the NRA standard (rings are half the diameter which equates to quarter the area). To see a plotting sheet calibrated in MOA, go here:

http://www.gbfclass.co.uk/index.php/hom ... ing-sheets

and you can have a look at the F-Class versions for different distances. The principle is the same though for all targets even though their dimensions might be different. Competitive shooters don't think inches but MOA. A short-distance sporting shooter is more likley to think inches and do the inch per 100 yards computation inside his or her head. Take a 150 yard shot at something and see the strike a bit high, think that was maybe six inches above the aiming mark, it's 150 yards (1.5 x 100), divide 6 by 1.5 and the scope setting is 4-MOA too high ... adjust downwards by that amount and try again.

MOA isn't the only such system. Military, police, and CSR etc competitors usually favour MilDot sights which are calibrated in miliradians