can anyone tell me the calculation to convert bullet drop in inches to moa?
surely it can't be that simple that inches = moa
for example if my bullet drops 9"@ 300yds it cant just be 9 moa!! or can it!

regards
griff

griff,
9 inches is pretty much 9 moa. a minute of angle is 1.047 inches. HTH
james

1 MOA is just a tick over an inch at 100 yards (I believe it is 1.08 inches)... I'm sure someone here has the exact number....

Based on that:

2 inches at 200 yards = 1 MOA
3 inches at 300 yards = 1 MOA
4 inches at 400 yards = 1 MOA

I imagine you are getting the drift here...

9 inches at 300 yards would be 3 MOA

Ken....

1 MOA = 1.04719756 inches @ 100 yds

Multiply it out every equivalent step


Equation --- 2*tan(1 MOA∙ π∕21600 )∙ 3600 inches = 1.04719756 inches

** 3600 is 100 yards in inches

all,
let me see If i've got this right.
@ 300yds out of 264 winnie my 140gn hornady (according to sierra ballistics) is dropping 6.14 inches, so if that was the drop @ 100yds then it would be approx 6 moa. So all being equal if I divide 6.14 by 300 then that should give the moa, or is it 6.14 divide by 3 x 1.047.
Pardon my mathematical expertize on this but I am having difficulty nowing whats what..

regards
griff

Simple way to do it:

MOA=((size of group)/(distance/100 yards))/1.0472

For Griff's example:

moa=(6.14/(300/100))/1.0472= 1.954

PLEASE NOTE: Size of Group is not bullet drop! (Thanks Vapodog)

The tan of 9 minutes of angle =.00261. There fore the tan 9Min.X 3600in.(100yds.) =9.396 in. roger

I really don't equate bullet drop to MOA.....MOA is normally used to express the pattern of dispersement from each other and not from the target......one could drop 30" and still shoot 1 MOA as I see it.

I agree with vapodog!

Harumph!

Bullet drop plays no part, IMO, in MOA.

MOA is an accuracy description.

MOA to drop is used when your doing "come ups".
He's 9" low at 300, how many clicks, on his 1/4 MOA/click, scope does he need? Answer: 11-12 clicks

Tailgunner,
thats what i'm after, how to calculate bullet drop in inches into moa clicks on the scope..

regards
griff

All,
knew what I wanted, just wasn't asking the right question.

regards
griff

Sorry boys I can't work this out!
what is the calculation to find out how many moa I have to raise my scope to adjust for bullet drop ie: 6.14" low @ 300 I now know how many clicks just what is the calculation..

regards
griff

quote:

Originally posted by griff:
can anyone tell me the calculation to convert bullet drop in inches to moa?
surely it can't be that simple that inches = moa
for example if my bullet drops 9"@ 300yds it cant just be 9 moa!! or can it!

regards
griff

Nope! At 300 yards, 9 MOA = 27". (Actually slightly more, but the difference is so small as to be inconsequential.....) And 9" @ 300 yards = a 3 MOA elevation difference in your sight adjustment...... In other words, if your bullet hits -9" from the point you want the bullet to hit at 300 yards, you come UP 3 MOA on your sight, and the bullet will hit 9" higher than it did before.

quote:

Originally posted by HL:
I agree with vapodog!

Harumph!

Bullet drop plays no part, IMO, in MOA.

MOA is an accuracy description.

MOA can also be a measure of sight change adjustment for those sights that ARE CALIBRATRED IN MOA, LIKE THE M1 AND M14 ARE!

If the bullet from an M1 is -9" @ 300 yards, you come up 3 clicks = 3 MOA, to rezero......

IF you have a scope with 1/4 MOA graduations on the adjustment dial, you must come up 12 clicks to raise POI 9" @ 300 yards.........

El Deguello,
I understand the need to adjust the scope 3 moa @ 300 yards if the drop is 9",
but how do you arrive at that, what is the calculation..
ie: @ 475yds my bullet drop is 30.83 "how do I convert those inches into moa on my scope?

regards
Griff

For rough calc's, you can use the following formulia. It should get you within 1 click (due to rounding errors).

Correction required / (distance x .01) = MOA adjustment.
30.8 / 4.75 = 6.48MOA. Call it 6.5 and come up 26 clicks

quote:

Originally posted by El Deguello:

quote:

Originally posted by griff:
can anyone tell me the calculation to convert bullet drop in inches to moa?
surely it can't be that simple that inches = moa
for example if my bullet drops 9"@ 300yds it cant just be 9 moa!! or can it!

regards
griff

Nope! At 300 yards, 9 MOA = 27". (Actually slightly more, but the difference is so small as to be inconsequential.....) And 9" @ 300 yards = a 3 MOA elevation difference in your sight adjustment...... In other words, if your bullet hits -9" from the point you want the bullet to hit at 300 yards, you come UP 3 MOA on your sight, and the bullet will hit 9" higher than it did before.

Actualy 9 MOA at 300 yard is 28.262 inches a MOA is 1.047 inches per 100 yards you calculated 1 inch per 100 yards and neglected to mmultiply 27 by 1.047 inches.True 1.262 inches isn't much, but as distance grows so does the margin of error...........

quote:

Originally posted by griff:
can anyone tell me the calculation to convert bullet drop in inches to moa?
surely it can't be that simple that inches = moa
for example if my bullet drops 9"@ 300yds it cant just be 9 moa!! or can it!

regards
griff

Inorder to turn drop in inches to minutes of angle. In your examplethe math is as follows;
9 divided by 3 divided 1.047=2.865 moa roumd it to 2.75 moa or round up to 3 moa
Another example; 26' drop at 400 yards
26 divided by 4 divided by 1.047=6.208 moa adjust scope 2 1/4 moa
the formular is divide inches in drop by the number of hundred yards ( 450 would be 4.5,525 yards would be 5.25,etc) by 1.047 ( which is inchs per hundred yards for a minute of angle) the answer is the minutes of angle of correction and mutiply the answer by for 1/4 moa adjustments and this is the number of clicks required
Or you can purchase the Exbal ballistics soft ware from Nightforce and the program will give correction in MOA,Mills,or Inchs per hundred yards for scopes that adjust in this manor (most but not all Leupold adjust in 1/4 inch at 100 yards and not 1/4 moa despite that the dials read 1/4 moa) Once you know your velocity and bullets BC this program is extremely useful for example. Sight in condition is an elevation of 500 feet above sea level,imput this info under sight-in conditions.When you go hunting you are hunting at 7000 feet of elevation imput this as field conditions and the program will calculate your exact bullet flight with the new conditions..........

quote:

Originally posted by griff:
El Deguello,
I understand the need to adjust the scope 3 moa @ 300 yards if the drop is 9",
but how do you arrive at that, what is the calculation..
ie: @ 475yds my bullet drop is 30.83 "how do I convert those inches into moa on my scope?

regards
Griff

Hell, GRIFF! It couldn't be simpler!! and no calculating is necessary:

1 MOA = 1" @ 100 yards (actually, 1.047")
1 MOA = 2" @ 200 yards (actually, 2.094")
1 MOA = 3" @ 300 yards (actually, 3.14")
1 MOA = 4" @ 400 yards (actually 4.188")
1 MOA = 10" @ 1000 yards, (actually, 10.47")etc. etc.

quote:

Originally posted by jwp475:

Actualy 9 MOA at 300 yard is 28.262 inches a MOA is 1.047 inches per 100 yards you calculated 1 inch per 100 yards and neglected to mmultiply 27 by 1.047 inches.True 1.262 inches isn't much, but as distance grows so does the margin of error...........

Yes, you are right! At the distances I shoot, and the size of my targets, the slight difference is inconsequential, so I use 1" = 1 MOA...... I am aware that an MOA is actually a miniscule fraction over 1"...... I really don't think a quarter of an inch is much at 300 yards..... few can hold close enough for it to be significant!