Understanding MOA

[Bug Splat]

I'm getting into the long range game. F-class looks mighty tempting as does long range hunting. I'll have my 6.5-284 Norma built and ready in a few weeks and I'm trying to get my head around calculating trajectory.

In order to understand the adjustments needed on my scope I made a simple chart which I think is right but I'm not sure. I somehow feel my math is wrong. This chart is assuming MOA is 1 inch. I know technically its a bit more but for learning purposes lets just call it 1 inch. 4 "clicks" equals 1 MOA. Fair enough? Ok, so are my numbers right?

[Arteel]

Picture doesn't work on my comp.

[Darklyte27]

http://www.calguns.net/calgunforum/showthread.php?t=154413

[Bug Splat]

Is anyone able to see the pic? Seems to work on all my machines.

[Young Version]

Yes, I can see it.

[Arteel]

Okay let me rephrase that, my comp doesn't work.

[GenLee]

I can't see it. on Vista pro, All I see is the prevebial FAIL red x

[GenLee]

I'm getting into the long range game. F-class looks mighty tempting as does long range hunting. I'll have my 6.5-284 Norma built and ready in a few weeks and I'm trying to get my head around calculating trajectory.

In order to understand the adjustments needed on my scope I made a simple chart which I think is right but I'm not sure. I somehow feel my math is wrong. This chart is assuming MOA is 1 inch. I know technically its a bit more but for learning purposes lets just call it 1 inch. 4 "clicks" equals 1 MOA. Fair enough? Ok, so are my numbers right?

You are correct in 4 clicks, If you have 1/4 not 1/8 adjustments.

[Darklyte27]

it wasnt working earlier, its working now though.

[ocabj]

The guy who wrote and operates JBM already made a trajectory card feature to generate ballistic results into a small form factor for printing and field use. I remember using it back in 2006 to create cards I keep in my range cart for emergency reference.

http://www.eskimo.com/~jbm/calculations-5.0/calculations.html

[buffybuster]

My recommendation:

DO NOT COUNT CLICKS!!! DO NOT USE INCHES FOR DOPE!!!

Only think in either MOA or Mils. Pick one and stick to it. All dope/wind calls and all adjustments in either MOA or Mils, whichever you decide on.

Will save you grief.

[Black Majik]

Something to remember regarding "Shooter's MOA" and "True MOA."

While 1" and 1.047" doesn't seem like much at 100, since you have your chart out to 1000y.. it can mean a big difference.

Since your scope seems to be using 1/4 MOA turrets, at 21 MOA to get out to 1000 yards we'll use that.

1.047" x 21 = 21.987"
21.987" x 10= 219.87"

1" x 21 = 21"
21 x 10 = 210"

Thus at 1000 yards you have a 9.87" error.

So, you'll have to check your specific scope to see whether it's measured 1MOA = 1" or 1 MOA = 1.047".

Of course, someone please correct me if I'm wrong, I'm learning too.

[MrNiceGuy]

OMG...my brain hurts.

[JoeC]

Visually, when looking down the scope at the target, how do all these numbers apply?
I'm completely new to this accuracy shooting stuff.

[Bug Splat]

Cool, thanks guys.

Yeah the .25 is just me rounding it off to make my brain hurt a little less while trying to understand it all. The way I was told to test for true MOA in your scope is to hit the range and measure. Once I cook up the best load for my rifle, I'll chrono FPS and test for my scope MOA and build a chart from those numbers.

Shooting with a 223 most of the time, I know what Mil-dot to hold on all the way out to 500 yards just from experience and trial and error. Never really needed to adjust the turrets until now.

Guess my teacher was right, I did need math when I grew up