Adjusting MOA Clicks

[harvey13118]

I can not find the old threads. But here goes. 22-250 40vmax 4100fps... 8.5X25 Leupold quarter clicks, 1.6" above bore.

Am I on the right thought process?

100yd O
200yds -1.07" +4.28 or up 5 clicks ??
300yds -5.59" +22.36 or up 23 clicks ??

Same load at 200 YD O

100tds +.54" -2.16 or down 2 clicks ???
200yds O
300yds -3.98 +15.92 or up 16 clicks ??

I think I have the exact MOA # 1.047"

Sorry if this real basis stuff BUT I am struggling to get a good grasp on this.

THESE DO NOT COME CLOSE TO WHAT I THINK I KNOW BASED ON PHYSICALLY WALKING 500 YDS WITH MY 308. The clicks up seem excessive.

TIA Harvey

 

[glo]

Hi Harvey, after posting I have reconsidered. I think you are confusing drop in inches with drop in minuets of angle,MOA).

Inches in drop/rise divided by yards divide by 100 equals drop/rise in MOA. A short cut is just to drop the zeros so you don’t have to divide the yards by 100,200 = 2, 300 = 3 etc…)

Drop/rise in MOA times 4 equals clicks up/down to zero.

Example:
100: 0”
200: -1.07” / 2 = .54moa; then .54moa x 4 = 2clicks
300: -3.98” / 3 = 1.33moa; then 1.33moa x 4 = 5clicks

It seems excessive because you are thinking in terms of clicks and inches of drop and not minuets of angle,MOA).
glo

 

[glo]

Hi folks,
I thought I’d just throw these next few paragraphs in as a technical note to for those confuses as to when minuets of angle or inches,centimeters) should be used.

Bullets in flight are affected by gravity and wind. The movement,drop, rise or left and right windage) of a bullet is measured in inches,centimeters). However, sights,scope, iron or aperture) and there adjustment are affected by light. Light when reflected back from the target, no matter how far in distance, moves in a straight line. This straight line of sight is measured in minuets of angle,MOA). Therefore, you must convert your bullet’s movement from inches to MOA to adjust your sights.

MOA is a unitless measurement; the farther the distance away from the sight radius the greater the multiplication of sight radius. That is, if your sight is adjusted to move a bullets impact 1 inch at 100 yards the bullets impact will move 2 inch at 200yards, 3 inch at 300yards and so on or 1 x 1 = 1, 1 x 2 = 2, 1 x 3 = 3 and so on. Your line of sight moves away from you as if you are standing in the middle of a big pie. An MOA is just a slice of the pie as measured at the thick end of that slice. The bigger the pie pan the larger the thick end of a slice of pie even if you are only cutting an 1/8 of a slice of the pie.

So, use inches to relate the movement of a bullet and use MOA to relate the needed adjustment of your sights. Once you have become proficient in understanding the differance between bullet movement and sight adjustment you can use MOA to relate to both the bullet movement and sight adjustments.
glo

 

[harvey13118]

Glo

You make it sound simple. Back to the range...

Missed a Coyote at 385 Yds,google earth) I guessed 350-400 or 375. So got to stewing over it. Turn scope up or hold over. Of course VERY strong wind from right to left so I had held over and into wind about 20". I shooting for head and made a serious impression with coyote.

But for what ever I've never fooled with scope except when shot Hi power silouette then I zeroed for each range and adjusted.

 

[alf]

Max Point blank range is 344 yds when zeroed at 298 yds.
Ist column- Range in yds.
2nd column-path in inches
3rd column-come ups in clicks
4th column-Velocity in fps
5th column-Energy in ft/lbs
6th column-Momentum in ft/lbs
7th column-ToF in sec.
8th column-Windage in clicks
last column-Optimal game weight

25 -0.8 13 3947 1384 22.55 0.019 0.1 1 148
50 -0.2 1 3800 1282 21.71 0.038 0.3 2 132
75 0.3 -1 3657 1188 20.90 0.058 0.6 3 117
100 0.6 -2 3520 1100 20.11 0.079 1.0 4 105
125 0.8 -2 3386 1018 19.35 0.101 1.6 5 93
150 0.7 -2 3257 942 18.61 0.123 2.4 6 83
175 0.5 -1 3131 870 17.89 0.147 3.3 7 74
200 0.0 0 3008 804 17.19 0.171 4.4 8 65
225 -0.7 1 2889 741 16.51 0.197 5.7 10 58
250 -1.7 3 2773 683 15.85 0.223 7.1 11 51
275 -2.9 4 2660 629 15.20 0.251 8.8 12 45
300 -4.5 6 2550 578 14.57 0.280 10.6 14 40
325 -6.4 8 2443 530 13.96 0.310 12.7 15 35
350 -8.7 9 2339 486 13.37 0.341 15.0 16 31
375 -11.3 12 2238 445 12.79 0.374 17.5 18 27
400 -14.4 14 2139 406 12.22 0.408 20.4 19 23
425 -18.0 16 2042 370 11.67 0.444 23.5 21 20
450 -22.1 19 1948 337 11.13 0.482 26.9 23 18
475 -26.7 21 1856 306 10.61 0.521 30.6 25 15
500 -32.0 24 1768 277 10.10 0.563 34.7 26 13
525 -38.0 28 1682 251 9.61 0.606 39.1 28 11
550 -44.8 31 1600 227 9.14 0.652 43.9 30 10
575 -52.4 35 1521 206 8.69 0.700 49.2 33 8
600 -60.9 39 1447 186 8.27 0.751 54.9 35 7

 

[glo]

Harvey,
I’ll take what you said as a compliment. Thank you. The truth be known bullet drop in inches, MOA and mil-dot ranging is for the most part simple. Your 20” hold over is known as Kentucky windage.

The reason,in my never to humble opinion) many shooters of old could shoot so well with the old black powder guns are because: one it was the gun they grew up with and two was there was only one load. This is also why many of our great snipers are so good. If you were a Marine sniper, you would probably, in your carrier, only used three different cartridges. Most likely you would only be issued one to work with: 7.62 NATO, .300 Win Mag or .50cal. If you spent 10, 15 or 20 years shooting the same cartridge you would eventually memorize all the drops, leads, hold overs, mil-dot half ranges and associated formulae.

If you can stick to one load or at least one load per game animal or paper target distance, things get al lot easier. Just remember drop in inches, MOA and mil-dot ranging are all separate things but all of them can be converted from one to another if you use the right equation.

I find the best tool is to tape a range card to the butt of your stock. JBM ballistics calculator is a great web site for trajectory. It also will calculate the MOA for bullet drop and leade.

 

[relliott]

Here's some useful calculations that may help.

To convert Mil to Moa & Moa to Mil:

Mil x 3.438 = Moa count

Moa / 3.438 = Mil count


These two would apply to this thread.


Inches to MOA

Path,drop in inches) /,range x 0.01) / 1.047= MOA

Moa to inches

Moa x,range x 0.01) x 1.047 = inches



Inches to Mils

Path,drop in inches) /,range x 0.01) / 3.6= Mils

 

[harvey13118]

Thank You for responding. Ya-all make it simple to figure. Gotta get busy now and check this out c if it works for me. More trigger time no cell phone what a way to relax.

Thanks again