# Cosine and Degrees formula help please.

Discussion in 'Long Range Hunting & Shooting' started by 300WSMMAD, Feb 3, 2009.

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208
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May 19, 2008
Hi Guys,

Ive just watched Shawn Carlocks DVD,which I thought was very informative.

But I have a question in relation to one area that I would like answering please.

I understand the formula for the up hill/ down hill calculations with the "cosine" but what is the formula if your angle indicator is in "degrees"?

If this has all ready been trashed to death I apoligise

2. ### Michael EicheleWell-Known Member

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Jan 6, 2003
Bullet drop from zero - (actual drop * angle multiplier)

Actual drop is drop from a level bore not angled up for a longer zero. In other words anything past the muzzle would be a negative number.

Example:

500 yards = 40" drop from a 300 yard zero, and 88" without a zero. The shot is a 30 degree angle. The angle multiplier for 30 degrees is 0.134

40 minus (88*.134) = 28.2"

88*.134 = 11.8

40-11.8 = 28.2

3. ### BuffalobobWriters Guild

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5,085
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Jun 12, 2001
If your angle indicator is in degrees you should build yourself a little conversion chart to carry with you.

Assuming you have a windows based computer then you find in
"Programs" and then in "accessories" a "calculator". In "view" click on "scientific". Then you will have access to the trigonometry functions of which one will be cosine "cos".

Enter the angle such as 5 degrees and click Cos and it will give you the value. Do this for values up to 30 degrees every two or three degrees. Now build you a table of angles and multipliers in MS Word using small font. Print out a few copies and get the scissors and cut them out and tape one to your stock.

What you have is a lot of decimal numbers that have to be used the way Meichele said. This has to be done out int the field.

As a wise man said several times, Long range shooting is all about math.

If you get a PDA and Exbal then it does all of this stuff automatically.

Messages:
208
Joined:
May 19, 2008
Thanks guys.

I know the PDAs do it for you, I just like to know how the basics of getting it.
and the only indicator I can get here is in Degrees, a cosine one would be way easier to work out,even with a simple calculator in the field.

5. ### cabelas90Well-Known Member

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247
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Dec 27, 2008
WOW my parents allways said i should have paid attention in math class!!!

6. ### CoyoterWell-Known Member

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92
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Nov 10, 2001
FYI, the Nightforce ballistics program has an incline chart built into it. You have to have excel on your computer to use it, but it's there and will print independently of other shot information.

Coyoter