I keep hearing Frank talk about turning off spin drift and other effects in ballistic programs to get a sort off “clean output” if you will. Is this possible to do in the Hornady 4DOF app? If not, is it worth it to go to Strelok Pro? Thanks.
Hornady 4DOF App
- Thread starter TM1107
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Hornady web site says:
The Hornady 4DOF® Ballistic Calculator accurately calculates the mass properties, aerodynamic properties and the responses of the projectile as it flies downrange as well as the movements of the projectile due to these responses such as spin drift, accurate Gyroscopic Stability (Sg) and Aerodynamic Jump (AJ). There is no Ballistic Coefficient (BC) needed or used in 4DOF®.
These are part of the calculation and there is no switch to disable in the Hornady Kestrel.
The Hornady 4DOF® Ballistic Calculator accurately calculates the mass properties, aerodynamic properties and the responses of the projectile as it flies downrange as well as the movements of the projectile due to these responses such as spin drift, accurate Gyroscopic Stability (Sg) and Aerodynamic Jump (AJ). There is no Ballistic Coefficient (BC) needed or used in 4DOF®.
These are part of the calculation and there is no switch to disable in the Hornady Kestrel.
I asked this question elsewhere but it may be better received/answered here:
Does the 4DOF software have the ability to enter a LH twist? I'm not seeing it on the iPhone app. Is it negated by something in the software whereby RH or LH does not matter?
Does the 4DOF software have the ability to enter a LH twist? I'm not seeing it on the iPhone app. Is it negated by something in the software whereby RH or LH does not matter?
I keep saying turn off SD in the 3DOF APPS like AB, Ballistics, etc,
3DOF does not calculate the SD, that is what 4DOF is for, those programs add a flourish which overestimates it. if you compare it as I noted. It appears you are only listening to 1/2 the story.
Listen to what I say, never said anything about Hornady because you don't have the fine tune details.
In the Kestrel we turn off the first WS1 to remove it and you can set the Azimuth to 0 along with the direction of fire. We also true it manually vs the advertised methods, that we have mentioned a ton.
Hornady is missing a few features, such as left or right, when you are not using the Earth Based effects it won't matter. Twist and bullet length are for SD and Azimuth is for CE.
I mention using JBM all the time, there is no SD, no CE, etc, there is no twist rate, and we praise it all the time for its accuracy. We don't need it, especially inside 1000 yards.
These things are add ons to 3DOF programs, hence my issues, remove them and the 3DOF software works great.
If you look Hornady SD number are just about 1/3 of the others so it's not adding a lot extra, but there is no way to remove AJ, or SD, etc on the phone. They limit the ability to tweak the output. I leave the wind in Hornady at 270 as it lines up correctly, I ignore the other directions.
with a Hornady bullet its a no brainer to use a free Hornady App, they have Doppler data which is tuned to the distances we speak about.
3DOF does not calculate the SD, that is what 4DOF is for, those programs add a flourish which overestimates it. if you compare it as I noted. It appears you are only listening to 1/2 the story.
Listen to what I say, never said anything about Hornady because you don't have the fine tune details.
In the Kestrel we turn off the first WS1 to remove it and you can set the Azimuth to 0 along with the direction of fire. We also true it manually vs the advertised methods, that we have mentioned a ton.
Hornady is missing a few features, such as left or right, when you are not using the Earth Based effects it won't matter. Twist and bullet length are for SD and Azimuth is for CE.
I mention using JBM all the time, there is no SD, no CE, etc, there is no twist rate, and we praise it all the time for its accuracy. We don't need it, especially inside 1000 yards.
These things are add ons to 3DOF programs, hence my issues, remove them and the 3DOF software works great.
If you look Hornady SD number are just about 1/3 of the others so it's not adding a lot extra, but there is no way to remove AJ, or SD, etc on the phone. They limit the ability to tweak the output. I leave the wind in Hornady at 270 as it lines up correctly, I ignore the other directions.
with a Hornady bullet its a no brainer to use a free Hornady App, they have Doppler data which is tuned to the distances we speak about.
As an FYI,
Look at the Hornady App and compare it to the SD in other programs, which I never mention it, Hornady is a lot less.
Here is my 260GT Barrel, 7.75 Twist Rate, (It's actually a 8.25 - 7.75 you only input 7.775) with a MV of 2850fps with a 136gr Scenar
I have my current conditions in there, and read it, then add this same information
You have 1 MOA or .3 Mils of SD at 1550 yards, so do you think I even need to worry aobut, hence the lack of discussion in this area with the Hornady App.
If you compare it, other apps will be much larger by comparison so we say to turn it off. If you listened to the podcast I said the other Apps were giving the user .6 to .8 at these same distances, and I said the right answer for me was .3 mils at the distances discussed.
You can easily see why I said turn it off. especially when it put me on the wrong side of the wind call.
Big difference in these Apps in this regards,
Look at the Hornady App and compare it to the SD in other programs, which I never mention it, Hornady is a lot less.
Here is my 260GT Barrel, 7.75 Twist Rate, (It's actually a 8.25 - 7.75 you only input 7.775) with a MV of 2850fps with a 136gr Scenar
I have my current conditions in there, and read it, then add this same information
You have 1 MOA or .3 Mils of SD at 1550 yards, so do you think I even need to worry aobut, hence the lack of discussion in this area with the Hornady App.
If you compare it, other apps will be much larger by comparison so we say to turn it off. If you listened to the podcast I said the other Apps were giving the user .6 to .8 at these same distances, and I said the right answer for me was .3 mils at the distances discussed.
You can easily see why I said turn it off. especially when it put me on the wrong side of the wind call.
Big difference in these Apps in this regards,
Even though 4dof Calls for less spin drift than the 3dof apps I still think it overestimates it. I use 4dof with the 139 scenar with wind set to 0 it calls for .46moa of spin at 800m for me or .64moa at 1000m. I've tested this at first light with no wind and it is too much.
Frank can you elaborate on why you turn off the WS1 and set the Azimuth to 0 along with the direction of fire in the kestrel?
What's the advertise truing method vs manual one taht you do?
Sorry if I make you repeat yourself but I'm really interested in what you mentioned.
What's the advertise truing method vs manual one taht you do?
Sorry if I make you repeat yourself but I'm really interested in what you mentioned.
FEATURE REQUEST
I would like to see the 4DOF app include the capability to adjust for turret click values. E.g a 2% error in indicated vs. actual adjustment. Hope that’s clear. It would be good to see that in the 4DOF kestrel too.
I would like to see the 4DOF app include the capability to adjust for turret click values. E.g a 2% error in indicated vs. actual adjustment. Hope that’s clear. It would be good to see that in the 4DOF kestrel too.
