Setup for Ballistic FTE

[WVshooter]

I've been doing some searching and reading on this topic and it's getting a little confusing. I'm new to this kind of equipment so can someone please tell me the basic setup for getting started with ballistic FTE on iPhone and what is the best way to input climate data from a kestrel 4500?

I've read some posts that make it sound like setting up and using DA is best and some that say use Temp, Humidity, and Station pressure.

Anyone using Ballistic FTE and a Kestrel with good results can you give me your basic settings in FTE and what climate data gives you best results just to get me started. I'm sure that the more I use it the more I'll learn but I'd like to get it setup in the ball park.

I may or may not have access to a chrono this week but I'll have the opportunity to shoot in the 500 to 1000 yard range and I assume that if I get my setup and weather data right I can fine tune the fps figures a little to try to match my actual shooting results out to 600 yards. Hopefully that will get me on paper at 1k.

 

[WVshooter]

Re: Setup for Ballistic FTE

Anything? Does it not make much difference which climate data you use?

 

[Lowlight]

Re: Setup for Ballistic FTE

If you have the Kestrel use the full input... DA is just a combination of those factors so why not let the machines work for you and use the complete data ? It is good, but more of a short cut rather than using the complete picture. It's better when using cards like the FDAC because you not relying on the calculator to calculate.

The biggest issue is not having a chronograph. It's one of the most important part of using a ballistic calculator. Without it the data is horribly swag'd.

But use Absolute Pressure, Temp, Humidity, and then get a chronograph.

 

[timelinex]

Re: Setup for Ballistic FTE

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">If you have the Kestrel use the full input... DA is just a combination of those factors so why not let the machines work for you and use the complete data ? It is good, but more of a short cut rather than using the complete picture. It's better when using cards like the FDAC because you not relying on the calculator to calculate.

The biggest issue is not having a chronograph. It's one of the most important part of using a ballistic calculator. Without it the data is horribly swag'd.

But use Absolute Pressure, Temp, Humidity, and then get a chronograph. </div></div>

So are you saying not to use DA?? I switched my ballistic FTE to DA because of everything I read on these forums. I was under the impression that using DA or all three values would give the same results.

 

[Lowlight]

Re: Setup for Ballistic FTE

I use DA with cards and not in my software,

If I am inputting into a ballistic calculator I like to give it as much data as possible.

Like anything there is a balance of when and where as well as in what context.

DA is more the answer to a set of variables where the calculator is more than capable in using the complete formula. The answer, DA is like a shortcut and has its own components that fit a bit of a different question.

When you look at DA in your Kestrel you'll notice it moves a lot and most use a rounded DA number. To the nearest 500 to 1000 ft or so. That is a clue. Why do you think DA data is rounded to whole numbers?

 

[WVshooter]

Re: Setup for Ballistic FTE

10-4, and thanks for the response. I'm working on trying to get across a Chrono before the trip.

I will use the complete data set for my calculator. If I can get across a chrono then all the better. If not I planned on shooting at 100 yard increments out to 4 or 500 yards and measuring my drop then referencing it with the calculator and adjusting the velocity to hopefully get it close to matching my drop.

 

[Petey]

Re: Setup for Ballistic FTE

I could never really figure out why FTE needed the speed of sound when set to DA so I went back to using absolute pressure, temp, and humidity. I thought SoS might just be a reference for the table output to show when the bullet goes transonic, but FTE will give different results when changing only the speed of sound.

If someone has an explanation I'd love to hear it.

 

[mouse07410]

Re: Setup for Ballistic FTE

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Petey</div><div class="ubbcode-body">I could never really figure out why FTE needed the speed of sound when set to DA so I went back to using absolute pressure, temp, and humidity. I thought SoS might just be a reference for the table output to show when the bullet goes transonic, but FTE will give different results when changing only the speed of sound.

If someone has an explanation I'd love to hear it.</div></div>
In short, drag (and its effects on the bullet and its trajectory) is tied to how near the projectile's velocity is to the speed of sound.

 

[timelinex]

Re: Setup for Ballistic FTE

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">I use DA with cards and not in my software,

If I am inputting into a ballistic calculator I like to give it as much data as possible.

Like anything there is a balance of when and where as well as in what context.

DA is more the answer to a set of variables where the calculator is more than capable in using the complete formula. The answer, DA is like a shortcut and has its own components that fit a bit of a different question.

When you look at DA in your Kestrel you'll notice it moves a lot and most use a rounded DA number. To the nearest 500 to 1000 ft or so. That is a clue. Why do you think DA data is rounded to whole numbers? </div></div>

I definitely notice the movement of the DA on the kestrel. I'm almost positive it doesn't get rounded off on the display of my kestrel though. It always shows it to the single digit, which is what is always fluctuation. But does that really even matter? Even for a 308 at a mile, a fluctuation of 100ft because of rounding is only like .1 mil. I wouldn't be surprised if the kestrel isn't accurate to that degree anyways(in judging pressure/humidty/temp).

Are you saying that the calculations done by the kestrel to arrive at the DA are less accurate than if the ballistic calculator crunched the 3 numbers, or that ballistic calculations based off all 3 variables are more accurate than calculations off an accurate DA.

I guess I'm just confused because I was under the impression that DA and the pressure/temp/humidity represent the same exact thing when it comes to ballistics, which is how much air/substance there is in the atmosphere,per unit, to cause drag.