Moa
 

allright so i am trying to understand how this works. at 100 yds. 1 click is 1/4 inch. what is it at 200,300,400?? and how does MOA work? can anybody explain this for me?

thanks,
yote

so the way i am understanding this is if i am shooting 400 yds. and i am sighted in to hit right on at 100 i need to go up 7 MOA. my scope is marked as 1 click =1/4 moa at 100 yds. and it has the 1,2,3,4 and so on marked on it. so at 400 yds i would turn it to 7. am i right?

-yote

one click if your scope is 1/4 moa at 100 would raise the point of impact 1/4 of an inch. 1/2" at 200 yards, or 3/4" at 300, or 1" at 400 yards.

it is screwy, and now im all screwed up thinking about it ,lol.

your scope probably has 4 marks then a bigger 1 marked out. 4 clicks to 1 moa. so if you neeeded 7 moa youll have to move it 28 clicks or 7 moa.

it would be 1/2 as many or x2 as many clicks if you had a 1/2moa scope or a 1/8 th(target)scope instead of a 1/4 moa scope. confused?

1/4 moa scopes are the norm so remember 4 clicks to an moa.

bring a pen and paper and right it all down , tape measure too. so you can remember it all in your way. there will be other people that will explain it better.

IF that is the value from your ballistics program (7 minutes needed to zero at 400)...

you would need to move 28 clicks. IF your turret was zeroed at 100 yds (rifle zero'd at 100 yds) to show 0 on the dial (with 4 clicks (1/4" clicks) to the next numerical reading); you would move your dail to position 7. A total of 28 clicks (7x4)..

change in elevation by clicks: +1/4" @ 100yds =~ 1/2" 200, ~= 3/4" @ 300, ~= 1"@400

[QUOTE=wolf308;1295282]one click if your scope is 1/4 moa at 100 would raise the point of impact 1/4 of an inch. 1/2" at 200 yards, or 3/4" at 300, or 1" at 400 yards.

Wolf has it right..

Say your rifle is shooting consistent 1" groupings (for simple math) at 100yards.. at 200 it'd shoot 2" groups, 300 - 3" groups, etc etc... 1000yards - 10" groups.

...if your rifle is shooting 1/2" groups at 100yrds, 200 would be 1" etc etc - get the picture??

Exact same thing relates to the MOA clicks on your scope (AS WOLF STATED)

all right thanks guys! i get it now! lol

geometry explains MOA
 

yote, MOAs are related to angular constants as related to the geometry of circles, arcs and chords of circles.

MOA means minute of angle, an angular value. 1 MOA = 1.04 or so inches at 100 yards. Shooters round that down to 1" at 100yds for convenience sake which is fine at the closer ranges.

Since MOAs are expressed as an angular value, as target distance increases downrange the spread of your bullets increases in a constant predictable way.
So then a 1MOA gun will shoot 1" at 100yds, 2" at 200, 4" at 400, 8" at 800 yards and so on (removing all other parameters like wind, shooter error, etc.).

Visualize it as a geometric problem. There are 360 degrees in a circle. 60 minutes per degree. So then 60x60 = 3,600 minutes to a circle. A minute of angle at 100 yards is known to be 1", which is the chord value of a 1MOA angle projected onto a 100yd radius circle. In other words, circumference of circle divided by 3,600 = 1.04" at 100yds. For simplicity sake lets keep it rounded to 1" at 100yds.

For a 100 yard shot, think of the rifle's muzzle as being at the centre of a big circle whose radius is 100yds. The bullets travel radially outward to cross the 100 yard circumference where your target is. They will not all cross in the same spot, but they'll cross in the same general area which is your group. The smaller that area, the more 'accurate' the rifle is. If you were to draw a line (chord) between the two furthest apart points of crossing (i.e. impact) at 100 yds, and this line measures 1" or less, you can say that your rifle is accurate to 1 MOA.

Say the bullets carried on and crossed another circumference 300yds out. Same rifle, same shots, same trajectories. Now draw a line (chord) between the two furthest apart points of impact at 300yds. This line would measure 3" or less, if your rifle is accurate to 1 MOA. If the distance between holes (the chord) is 6" at 300yds, you've learned that your 1 MOA 100yd rifle is a 2 MOA 300yd rifle, or that your technique needs development, or your load needs more development, or....

There are 360 degrees in a circle. 60 minutes per degree. 60 seconds per minute. 60x60 = 3,600 minutes to a circle. Since rifles are not always shot at set distances, it is handy to simply refer to their accuracy potential in angular terms, i.e. MOA capability.

To prove it to yourself get a hold of a big piece of gridded paper. Draw an angle, any angle. Now you see two divergent lines that share a common point of origin. This point is where the rifle muzzle is when the shots are fired. Notice how the distance between the divergent lines increases in a constant way. Each bullet fired by that rifle will land within the angular area between these lines. That's MOA.

Now your scope clicks. Like Wolf said, if 1/4 click moves your average point of impact by 1/4" at 100yds, that same click value will move your point of impact twice as much at 200, four times as much at 400.

Dial in enough clicks to go up 2" at 100 (that's 8 clicks for you) and you'll get an 8" rise in average point of impact at 400yds.

Simple answer is "yes". Each click is 1/4 MOA, so therefore every 4 clicks there should be an MOA number marked, which you refer to as 1,2,3,4, etc. If your bullet is 7MOA low at 400 yards, then just spin the elevation dial up to "7", which should equal 28 clicks. But you're doing it right by turning the dial to the MOA correction needed (7MOA), rather than counting each click.

And all this works if your scope actually tracks to a true 1/4 MOA per click, and your not faced with other annomolies like parralax, and enviromental changes such as temperature, air desnity, and head vs. tail winds etc.

Not to mention that unless you have actually chronographed the load in your rifle to determine the actual muzzle velocity, the charts or calculations, could have substantial error at longer distances.

:acigar:

There ya go again, confusing the issue with facts...the nerve of some guys.:sign0176:

Next thing ya know you'll be telling these fellers they gotta practice, to accomplish what they see on TV.
:fighting0030::scared0018:

Practise,what for, all that you need to do is watch "Best of the West" once a week, and you will be an expert long range shooter in no time at all.:)

I want to hunt deer at 1500 yards so bought the Husquemaw scope I saw on TV. The store clerk bore-sighted it for me, said he zeroed it at 1500 yards. Picking it up tonight and heading out the door in the am ready for my big long-range hunt.

It's a new rifle with all the bells and whistles: fluted ss barrel, skeletonized bolt handle, jeweled bolt, see-through rings, so I know its accurate. In 30-378. They kicked in a box of ammo (sweet deal) so I'm good to go.

Great post....not far from the truth talking to "some folks".....

"Trollin trollin trollin.......keep the troll train rollin......trollin trollin trollin.....Bull#$%&" :)

LC :)

;-)