# trajectory zero program

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Savageman69, Oct 27, 2009.

1. ### Savageman69Well-Known Member

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i have a few questions about the trajectory zero angle program, i got it from a member on this site so i figured its a good place to ask.

1. when i first used it, i input the twist rate. i have a 1:16 twist 22 inch barrel
so is it a 1 1/4 twist rate?
as i understand a 1:16 twist in a 16 inch barrel would be 1 twist rate right?
so in the program i put in 1.25 for twist rate at first it accepted that now it changes to 6:00 when i input 1.25? am i doing this right? and is this correct? just a different way of saying the same thing?

2.what is the impact ht. its impact height correct? if so what is that? is that the height of the hole the bullet makes? if not how do i measure it?

3. angle of fire, is level shooting 0 degrees? and shooting a sleight down angle would that be like 350 degrees or am way off? if so what is the correct way to use this function?

4.bullet length is that the projectile? or the projectile and cartrige combined if i put in the projectile length it spits out 360 inches of wind at 100 yds so thats not right, when i put the cartrige and projectile length i get 1/2 inch wind at 100 yds and thats about what i see at the range, so i think thats right.

please answer any questions you can even if you only know how to answer one of my questions please do, any answers you can give will help, thanks

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3. ### Savageman69Well-Known Member

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ahhh thank you so much for your help (and the program btw)

one last thing if you would be so kind, i tried to enter 16 for twist rate and it wont let me do so it, the program just puts it at 0:00 but i get a result almost exactly what i see at the range, i think the variation at the range is operator error so thats fine, and i dont enter wind cuz at my range there really isnt any
for the twist rate does the length of the barrel change the value, i have a 22 inch barrel is that still a twist of 16?

but everything else helped out alot thank you, thank you

4. ### EagletWell-Known Member

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Let me try to help with part of your question.
1:16 twist rate means that the twist makes one full turn in 16 inches. The
barrel length does not matter. Your barrel could be any length you want
to dream up and still be 1:16 twist rate.

Last edited: Oct 28, 2009
5. ### joel0407Well-Known Member

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And where do I get this program?

6. ### Michael EicheleWell-Known Member

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That is because at one time you entered 1:16 and teh program changed the field value to time. Now that you enter a number other than time format, it defaults to 0:00.

Right click the box, select 'format cells' and select general number. Then enter just plain 16.

Hope that helps!

7. ### Savageman69Well-Known Member

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that does indeed help thanks a million i fixed it

8. ### Michael EicheleWell-Known Member

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PM me your email and I will send you one.

9. ### joel0407Well-Known Member

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So is it good???

Where can I get it????

10. ### Michael EicheleWell-Known Member

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I think it is. But then again I am biased.

I created it using MS excel. This was done for several reasons. 1: it can be used on most pocket PC's using pocket excel. 2: you dont have to install a large program that creates complications on your computer. 3: it doesnt take up much space. It takes up less space than a picture file. 4: you can copy and paste as many as you need and rename them for different loads. It is accurate. I use these calculations for all of my LR shooting. It was designed to be simple and effective. There is no clutter nor 50 lines of bullet drop. You enter the yardage and you get one drop.

PM me your email and I will send you one.

Last edited: Oct 29, 2009
11. ### Savageman69Well-Known Member

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id say you did a fantastic job designing the program, compared to other programs ive looked at for \$30-\$40 yours blows them away it has all the same parameters, a quick explination/directions on how to use the program to eliminate any confusion would bump the program from an A+ rating to an A++

i think a small notepad file with directions for people like me would really help and it would save you some time and hassle answering any questions.

thanks for your willingness to share your work. i love this program, anyone else that uses it will too