Ballistic programs that dont agree

[shawnb]

Im going to go out shooting tomorrow to see which is closest. I have a spot to reach out to 1910 yards so we will see

Anyone care to shed some info or other findings similar like i have. This is a 225 eld out of my version of the prc.

These are the windows from my last trip out and i found out right away i had a loose scope after a 3 hour drive to the hills and no drivers to tighten it back up. So i will see tomorrow how things pan out.

Also interesting to see applied ballistics puts the 212 eld at .359g7 and the 215 hybrid at .358g7.....

 

[milo-2]

Im going to go out shooting tomorrow to see which is closest. I have a spot to reach out to 1910 yards so we will see

Anyone care to shed some info or other findings similar like i have. This is a 225 eld out of my version of the prc.

These are the windows from my last trip out and i found out right away i had a loose scope after a 3 hour drive to the hills and no drivers to tighten it back up. So i will see tomorrow how things pan out.

Also interesting to see applied ballistics puts the 212 eld at .359g7 and the 215 hybrid at .358g7.....View attachment 151066 View attachment 151067 View attachment 151068

I have found getting 2 diff apps to match is hard. My main experience is Shooter and AB. Yesterday I tried help a friend who bought Strelock Pro, I had AB, but I was able to manipulate numbers better in AB, we could find nowhere in Strelock to enter elevation, and it proved to be an issue.
You have a 1.4 mil variance in dope at 1780, a lot of vertical at that distance. If you are seeking advice, I would kick out your top calcs and rely on 4 DOF as it was designed for Hornady bullets, keeping AB as a solid backup. There comes a time when a guy just needs to launch a couple rds, visualize what happens and regroup. By regroup I mean manipulate inputs to match actuals. We have all struggled with an app, and always it is a box not checked, or too many checked, or a number off slightly, or the dreaded inflated bc numbers, which is becoming more scarce yearly.

 

[User4302021]

... we could find nowhere in Strelock to enter elevation, and it proved to be an issue.

What do you mean by this? I have been using Strelok Pro for 4 years now, you can input everything.

I have Strelok Pro, Trasol, AB, 4DOF, and Ballistic Arc.

I use them all to some extent, but Strelok Pro has been my favorite by far.

 

[Rhovee]

Report back with your findings.

 

[BallisticsGuy]

Being as I publish my own, I have some expertise here. Calculators implement the mathematics in different ways, many use different mathematical models and then you've got little switches/toggles/dials in the app itself which are not always totally clear to the layman as to their effect or their correct usage. When I built mine I used an existing app that had a critical bug in it (which I fixed) as the foundation but then I tweaked the way that the mathematics was implemented and exposed some additional inputs to give results that I feel are more precise WHEN USED CORRECTLY. In order to validate my calculator's numbers I compared hundreds of input sets across a great gooey gob of different calculators which all supported G1 BC's. What I noticed was, excluding my own, there was a normal variance of .5MOA across the set of calculator apps that I was comparing. So, that gave me a basis by which to compare my own calculator to the others. When the inter-app variance between mine and the others I tested against was within roughly .5moa then I was reasonably sure that I hadn't made any critical errors and the results could be useful.

Newer calculators like 4dof have come out since I published mine and there is some not small disagreement between it and other apps. I haven't tested much against 4dof but some of my shooting buddies do use it to build their dope cards for our matches and they seem to get very good results with it and the ELD series of bullets.

 

[shawnb]

I will point out that the website version of 4dof vs the app version is closer to the other calculations. Not sure why they dont agree with eachother.

I have my velocity from a magnetospeed, enviromentals from a kestrel, scope tracks true. Ive shot this out to 1000 very consistently but only had the magneto recently and it tells me average 2952fps. Single digit SD.

So we will see later this morning once the little one goes down for a nap.

Ill keep you posted on what i find. Please note this is the original run of 225's not the new(current) version.

 

[shawnb]

It has just been in the last while that ive noticed this as i started shooting to a mile and farther. The 4dof and AB match great out to 1000-1250 to within .1mil of eachother.
After that is when they start separating.

Now that all screws are tightened and torqued im interested to see which will get me closer and maybe how much i have to adjust things.

 

[milo-2]

What do you mean by this? I have been using Strelok Pro for 4 years now, you can input everything.

I have Strelok Pro, Trasol, AB, 4DOF, and Ballistic Arc.

I use them all to some extent, but Strelok Pro has been my favorite by far.

Like I said, we cannot figure just where you enter elevation, now my Godson uses Pro and I know we could on his app, and it is close.

 

[Triple BB]

I will point out that the website version of 4dof vs the app version is closer to the other calculations. Not sure why they dont agree with eachother.

I have my velocity from a magnetospeed, enviromentals from a kestrel, scope tracks true. Ive shot this out to 10So we will see later this morning once the little one goes down for a nap.

Ill keep you posted on what i find. Please note this is the original run

I will point out that the website version of 4dof vs the app version is closer to the other calculations. Not sure why they dont agree with eachother.

I have my velocity from a magnetospeed, enviromentals from a kestrel, scope tracks true. Ive shot this out to 1000 very consistently but only had the magneto recently and it tells me average 2952fps. Single digit SD.

I used my Magnetospeed for average velocity in my Sig ABS. I was getting some MOA variances at different distances. My Smith suggested playing around with velocity in the Sig and see if I couldn't dial things in a bit tighter. It worked. He uses Doppler, but I didn't want to pay him for that. Seems like you might see some of the same differences with online apps and a Magneto or some of the other chrony's...

 

[Rhovee]

I tested my Magneto against Labradar it was within 3 FPS of each shot over 5 rounds.

 

[User4302021]

Like I said, we cannot figure just where you enter elevation, now my Godson uses Pro and I know we could on his app, and it is close.

On the iOS version, it is the weather bar immediately above the load window on the main page. There is option for pressure altitude (inHg), temp and humidity, or DA.

 

[bigngreen]

When your looking at apps like AB, Shooter, and Strelok they run the same basic solver, AB is the more robust version and I can run it farther than any other program using the custom profiles or building my own, the others will start dropping of with more range.
When you dig into a program like Coldbore or Transol and maybe the 4 DOF your looking at a different base solver and you need to explore different methods to get correct and repeatable results, using a BC from Litz may not fit the other solvers as well as ones from their own testing based on their software. There are holes in most software, very few of us will see them in practical application.
Coldbore is the sweetest solver I've ran BUT it's on a crap platform and has just been passed by which sucks.
Any more the only solvers I'm interested in are loaded on a Kestrel, it's really amazing to sit and watch a live solution rolling of a Kestrel on a vane 50 yards away from you!!

 

[emp1953]

The math is the math. If they vary by much someone somewhere has implemented one of the inputs incorrectly, a units conversion issue??

 

[shawnb]

All inputs are the same. Give it a try if you have the programs.

The thread is not whether inputs are all the same. Its about people that have found big differences berween programs that are said to be good. The ones that always seem to come up are AB and the 4DOF. And if they have found things just dont line up, describe how they fixed or adjusted things to help people out.

Ballisticguy and bigngreen, thanks for your input.