Range Report Introducing "Shooter", ballistics for Android!

Re: Introducing "Shooter", ballistics for Android!

It has gotten better with each update, but in my view adding kb closure and shrinking screen to reduce scrolling just made it a much more friendly app.

The screen is still slightly oversized, hiding the target header, but its damn near perfect.

Its just a lot more polished and efficient to use now.
We old bastards like that shit.
laugh.gif
 
Re: Introducing "Shooter", ballistics for Android!

Haha well good. As of now, the app does what I had envisioned it to do from my first thought -- I can choose a ballistics profile easily, make a calculation quickly and get my corrections. That is the most important thing for an app like this. So I hope everyone can get good use out of it as it stands at this point. But I do have bigger plans to not only polish, but add more "cool" features like you see in iPhone apps. As I said before, it's an evolution. Some choose to keep their app to themselves until they develop lots of features into it. I chose to make this app free and let you see/use my progress as it evolves.
 
Re: Introducing "Shooter", ballistics for Android!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Swedish guy</div><div class="ubbcode-body">Sean,

would a meter/ m/s wind and C temp version be in the making,

as a very happy european user I would love that stuff.

/Chris </div></div>
Yessir, I will include a setting for this.
 
Re: Introducing "Shooter", ballistics for Android!

Sean, thanks for this. I was feeling a hole in my android for a ballistics program and you're filling it beautifully.

Once the dust has settled, my only request would be a "loophole" function
cool.gif


Thanks again, Sean, you're the man.


-Wes
 
Re: Introducing "Shooter", ballistics for Android!

I have a request... I've been using the program for about 2 weeks now and LOVE it. Any chance of "locking" the top name bar when scrolling thru the table data? I have to keep scrolling back to the top to see what column I'm referencing.
Other than that, I'm good with what you have.
Oh, any chance of alphabetizing the initial selection list? It always stays like you enter the weapon. I'd like to see it go from small at the top to large at the bottom.
Thanks

dennis the menance
 
Re: Introducing "Shooter", ballistics for Android!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cdennyb</div><div class="ubbcode-body">I have a request... I've been using the program for about 2 weeks now and LOVE it. Any chance of "locking" the top name bar when scrolling thru the table data? I have to keep scrolling back to the top to see what column I'm referencing.
Other than that, I'm good with what you have.
Oh, any chance of alphabetizing the initial selection list? It always stays like you enter the weapon. I'd like to see it go from small at the top to large at the bottom.
Thanks

dennis the menance </div></div>

The next release (v2.0) will have support for stepped ballistics coefficients and preferences for profile sorting order (as you mentioned), distance/atmosphere/other unit selection (for you damn europeans/canadians ;p), wind-input unit (degrees/clock), desired mildot spec, whether or not to save last distance/atmosphere entered, range table step size, and range table sorting.

I'll see about locking range table heading in this next release too.
 
Re: Introducing "Shooter", ballistics for Android!

Sean, thank you so much for this wonderful app. I've been waiting for a long time for something like this, and you've delivered wonderfully. Please incorporate a donation button into your next release
laugh.gif


ETA: Or post your paypal address here
smile.gif
 
Re: Introducing "Shooter", ballistics for Android!

Version 2.0 uploaded.

Changes:

- There is now metric support. (please test and report to me any issues)
- Stepped ballistic coefficients for greater accuracy (please test this out and compare with known good results and let me know if everything is coming out right)
- Sort your profile screen
- Pick your desired mil-dot specification (USMC,ARMY)
- Save your last-entered distance and atmosphere
- Pick your step-size for range table
- Pick desired sorting order for range table
- Timer function for the target angle calculator.

Most of these changes are accessible in the new "Preferences" section which you can access by clicking the Menu button on the profile screen.

I released some big changes here, so I'm sure there will be bugs. Please post bugs you find here or email me at [email protected].

I didn't get to the fixed header for the range table, hopefully in 2.1 I will get that.

Enjoy fellas, and please give your feedback.
 
Re: Introducing "Shooter", ballistics for Android!

While I have not tried to duplicate Swedish guy's problem, this works great.

Nice work, Sean!
Thank you for the option of wind direction in degrees or clock-hours.
The save distance and save atmosphere choices are helpful as well.
The new table options are nice.
I will tinker with the stepped BC's tonight. Cool feature.
The angle timer is a great idea....but I am not sure the beep will be a popular thing. Still, I commend you for coming up with a solution. It works perfectly.

Thank you, sir!
This program is an excellent tool and this update has alot of that "polish" to it.
 
Re: Introducing "Shooter", ballistics for Android!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Swedish guy</div><div class="ubbcode-body">Sean- I had no luck getting the metric part started,

perhaps I am doing it wrong, I´ll have to get back to doing it right after work today.

Best regards Chris </div></div>After you start up the app, click the Menu button. You should see Preferences option come up, that is where you can define units.
 
Re: Introducing "Shooter", ballistics for Android!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rafael</div><div class="ubbcode-body">The angle timer is a great idea....but I am not sure the beep will be a popular thing.</div></div>Yeah, I wasn't sure either
wink.gif
Maybe a vibrate just when it's done would be more appropriate.
 
Re: Introducing "Shooter", ballistics for Android!

It shows you know how to work towards a solution. It certainly does the job.

I know it involves new code, but....
How about just touching the screen, anywhere on the screen, to lock in the angle? The touch area would have to cover the whole screen since you can't see it when you are sighting.
 
Re: Introducing "Shooter", ballistics for Android!

Density altitude is not particularly useful on a handheld system which is carried in the field.

In order to calculate the density altitude, you must know the atmospheric pressure, the temperature, and the moisture content of the air - normally expressed as relative humidity.

Those are exactly the parameters which every ballistic program uses to calculate air density.

If you have a unit like a Kestrel which calculates density altitude, you already have a system which measures those parameters.

Density altitude is a concept which is useful for calculating a firing table which may be printed and carried in the field for use in the absence of a handheld ballistic program.

Such a table may be calculated by any ballistic program. If the reader doesn't know how to do that, this article may be useful:

Making Ballistic Cards Using Density Altitude
 
Re: Introducing "Shooter", ballistics for Android!

Sean, the display of the different units (Mils, MOA, and IPHY) when you press "compute solution" is missing on my app. Also, it displays as (Mils_USMC), which has a weird wrapping effect. I'll hook my Droid up to the computer later and take a screenshot.

Did you intentionally delete the stepped display? I really liked that feature. Also, would it be possible to simply show Mils instead of Mils_USMC, once you've chosen Army or MC Mils?

Thank you again for all your hard work. This tool gets better every day.
 
Re: Introducing "Shooter", ballistics for Android!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: WusteHase</div><div class="ubbcode-body">Sean, the display of the different units (Mils, MOA, and IPHY) when you press "compute solution" is missing on my app. Also, it displays as (Mils_USMC), which has a weird wrapping effect. I'll hook my Droid up to the computer later and take a screenshot.

Did you intentionally delete the stepped display? I really liked that feature. Also, would it be possible to simply show Mils instead of Mils_USMC, once you've chosen Army or MC Mils?

Thank you again for all your hard work. This tool gets better every day. </div></div>

Interesting, I cannot get that behavior. No I did not remove the multiple-solution-unit display. and it's odd it's showing you the Mils spec. Would you please tell me what you have set for your preferences options and what data you entering when this occurs? I'll get it fixed up.

EDIT: Nevermind, I reproduced the problem. Fix soon.
 
Re: Introducing "Shooter", ballistics for Android!

That Mils display issue is fixed now and uploaded as version 2.1. Since several people use mils as the primary solution unit, I didn't want to wait for other additions before fixing.
 
Re: Introducing "Shooter", ballistics for Android!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: WusteHase</div><div class="ubbcode-body">Sean, thank you so much for this wonderful app. I've been waiting for a long time for something like this, and you've delivered wonderfully.<span style="font-weight: bold"> Please incorporate a donation button into your next release
laugh.gif


ETA: Or post your paypal address here
smile.gif
</span></div></div>

I second that notion; if not paypal, then beerpal, either one...
 
Re: Introducing "Shooter", ballistics for Android!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cf7go</div><div class="ubbcode-body">I wish they had something like this for the Palm Pre. </div></div>
Have you tried "Pocket PSSF"?
Do a Google search for that term and you will find it.

A cheap way to get an Andoid device is to go with the Archos 5, pocket internet tablet. A buddy has one and it is very impressive.
About $250.00. He has loaded alot of apps and they all work, but he has not tried Shooter yet.
 
Re: Introducing "Shooter", ballistics for Android!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rafael</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cf7go</div><div class="ubbcode-body">I wish they had something like this for the Palm Pre. </div></div>
Have you tried "Pocket PSSF"?
Do a Google search for that term and you will find it.

A cheap way to get an Andoid device is to go with the Archos 5, pocket internet tablet. A buddy has one and it is very impressive.
About $250.00. He has loaded alot of apps and they all work, but he has not tried Shooter yet. </div></div>

The PRE has a different OS. So I dont think that will work. I also have a Treo 800 laying around. Are there apps for that?
 
Re: Introducing "Shooter", ballistics for Android!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: seankndy</div><div class="ubbcode-body">That Mils display issue is fixed now and uploaded as version 2.1. Since several people use mils as the primary solution unit, I didn't want to wait for other additions before fixing. </div></div>

Wow, talk about a fast response! The ability to do stuff like this is why I love the Android platform.

I'll second (or third or fourth) the request for a place, maybe in the settings menu or somewhere unobtrusive, for a donation link. I paid for my iPhone ballistics software, and I'd be glad to kick in a few bucks for this to keep development going!
 
Re: Introducing "Shooter", ballistics for Android!

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">If I have a Krestel and a density altitude then I could just type one number in and not three. Correct?</div></div>

Yes. But temperature is the parameter which changes much, so most of the time in the field, you'll only be entering that number anyway. On my field units, I leave the RH set at 50 percent all the time, and not changing it from that figure makes an insignificant difference.

So, IMO, having DA in a field unit is an unnecessary complication. I have a program with that feature, and I never use it.
 
Re: Introducing "Shooter", ballistics for Android!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lindy</div><div class="ubbcode-body">Density altitude is not particularly useful on a handheld system which is carried in the field.

In order to calculate the density altitude, you must know the atmospheric pressure, the temperature, and the moisture content of the air - normally expressed as relative humidity.

Those are exactly the parameters which every ballistic program uses to calculate air density.

If you have a unit like a Kestrel which calculates density altitude, you already have a system which measures those parameters.

Density altitude is a concept which is useful for calculating a firing table which may be printed and carried in the field for use in the absence of a handheld ballistic program.

Such a table may be calculated by any ballistic program. If the reader doesn't know how to do that, this article may be useful:

Making Ballistic Cards Using Density Altitude
</div></div>

Lindy, not trying to be contentious or disrespectful but here is a gathered information that would be helpful to many:

1) If the shooter has a Kestrel with DA capability, then it’s much easier and less error-prone to enter just one value than 3 or 4 (Temperature, Humidity, Altitude and Barometric Pressure, or Station Pressure -less altitude-)

2) So, it’s good idea and a very important feature, to have a mobile-based program that can take DA as a single atmospheric parameter.

3) If the underlying model used by the ballistics engine, such as in LoadBase 3.0, is the exact one, then DA can yield the same accuracy as the traditional parameters in order to model the Air Density Ratio, which is the only and vital parameter that matters to calculate in exterior ballistics.

4) Under LR situations it’s critical to account for the difference in Sight-In and actual Field Conditions. Using the current conditions will not account for that. And the difference can be substantial as range increases and conditions differ from the Sight-In ones.

5) So far, the only program that can calculate a DA table (exact model) is LoadBase 3.0 For sure more programs in the future will be required to add such capability.

Regards

 
Re: Introducing "Shooter", ballistics for Android!

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">2) So, it’s good idea and a very important feature, to have a mobile-based program that can take DA as a single atmospheric parameter.</div></div>

Well, I've been using PDA-based ballistic programs in the field for 6 years. I've found that unnecessary. Perhaps those who are error-prone may find it more useful.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">3) If the underlying model used by the ballistics engine, such as in LoadBase 3.0, is the exact one, then DA can yield the same accuracy as the traditional parameters in order to model the Air Density Ratio, which is the only and vital parameter that matters to calculate in exterior ballistics.</div></div>

The exactness of the model in use by the ballistics engine has <span style="font-style: italic">nothing</span> to do with the way the parameters are entered. Entering them as three separate numbers is as exact as entering them as one number.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">4) Under LR situations it’s critical to account for the difference in Sight-In and actual Field Conditions. Using the current conditions will not account for that. And the difference can be substantial as range increases and conditions differ from the Sight-In ones.</div></div>

While that's true, it's most important for people who are using zeroes at extended ranges with scopes of limited elevation capability. Since they will have to be shot off bases with a lot of slant, and will be unable to use a short-range zero, certainly accomodating changes from the sight-in conditions is important - for them.

In addition, several PDA-based ballistics programs accomodate changes from sight-in conditions, which is not a function of being able to enter air-data parameters as density altitude.

Most shooters who are not shooting at extra-long range are using zeroes at 100 yards or meters, and that factor is unimportant at such ranges.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">5) So far, the only program that can calculate a DA table (exact model) is LoadBase 3.0 For sure more programs in the future will be required to add such capability.</div></div>

If you're referring to PDA programs, you're probably correct, since most programs are not generating a DA table as such.

Which is only important if you think that having the capability to input data in the form of a density altitude is important - which I don't.

If you enter the air density parameters individually, LoadBase is no more accurate with respect to its air density calculation than other programs. That calculation is essentially trivial and well-known.

 
Re: Introducing "Shooter", ballistics for Android!

Sean;
Great job, once again!

One itsy-bitsy suggestion.....can the windage adjustments be changed from +/- to L/R and elevation to U and D?


Also, since there is no room in the Market comment area to address all concerns voiced there......

One person mentioned the need for a barrel-length setting in profiles. Barrel length makes no difference to the programs result since it is based on muzzle-velocity. If you shoot the same load in two different guns with different lengths, you will need a separate profile for the velocity difference between guns.
If you want to differentiate between profiles that are otherwise identical, you should just change the title of the profile,
Call it "175MK Win88", or "175MK Rem-sendero", or even "175MK 26" bbl". Of course, two rifles with the same barrel length should have different profiles because they will likely not share common data like sight-height and scope adjustments/reticle, and velocity.

Another person sugested GPS coordinates for altitude. I find it easier to leave altitide at zero and enter a direct barometer reading. This way you are only dealing with one variable.
If you must enter altitude, there is a free app on the market called "GPS Status" that will give you an altitude reading. As to GPS derived weather......I trust my Kestrel more than I trust the weather data for the "nearest" station.

Someone mentioned an error when yardage is input as a decimal value. Mine won't accept a decimal value.....maybe Sean fixed this already. Still, do we really need a solution with better resolution than 1 yard?

Someone else complained he didn't like Sean's choice of the Icon for the program.
Dude! Really? Dude? Really!
laugh.gif



Of course I do not speak for Sean. The above is just my opinion.
 
Re: Introducing "Shooter", ballistics for Android!

Yeah some of them piss me off ;p The people that piss me off the most are the ones bitching about not having a "Help" section.

The application *was* crashing on decimal input for yardage and yes, I fixed it by not allowing them to enter a decimal. Like shit they need that extra 1 foot of difference in there.

GPS altitude I'd like to do. Some will use it, some won't. Definitely will be only an option and not automatic.

And actually that dude who complained about the icon having a sharp upper left edge was right, and I got it fixed too :p It's nice and round as of v2.0.
wink.gif


Oh, and about your wind values, yes... that is done. The range-table was showing it the way you preferred already so it was inconsistent. Next release will have it like that.
 
Re: Introducing "Shooter", ballistics for Android!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lindy</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">2) So, it’s good idea and a very important feature, to have a mobile-based program that can take DA as a single atmospheric parameter.</div></div>

Well, I've been using PDA-based ballistic programs in the field for 6 years. I've found that unnecessary. Perhaps those who are error-prone may find it more useful.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">3) If the underlying model used by the ballistics engine, such as in LoadBase 3.0, is the exact one, then DA can yield the same accuracy as the traditional parameters in order to model the Air Density Ratio, which is the only and vital parameter that matters to calculate in exterior ballistics.</div></div>

The exactness of the model in use by the ballistics engine has <span style="font-style: italic">nothing</span> to do with the way the parameters are entered. Entering them as three separate numbers is as exact as entering them as one number.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">4) Under LR situations it’s critical to account for the difference in Sight-In and actual Field Conditions. Using the current conditions will not account for that. And the difference can be substantial as range increases and conditions differ from the Sight-In ones.</div></div>

While that's true, it's most important for people who are using zeroes at extended ranges with scopes of limited elevation capability. Since they will have to be shot off bases with a lot of slant, and will be unable to use a short-range zero, certainly accomodating changes from the sight-in conditions is important - for them.

In addition, several PDA-based ballistics programs accomodate changes from sight-in conditions, which is not a function of being able to enter air-data parameters as density altitude.

Most shooters who are not shooting at extra-long range are using zeroes at 100 yards or meters, and that factor is unimportant at such ranges.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">5) So far, the only program that can calculate a DA table (exact model) is LoadBase 3.0 For sure more programs in the future will be required to add such capability.</div></div>

If you're referring to PDA programs, you're probably correct, since most programs are not generating a DA table as such.

Which is only important if you think that having the capability to input data in the form of a density altitude is important - which I don't.

If you enter the air density parameters individually, LoadBase is no more accurate with respect to its air density calculation than other programs. That calculation is essentially trivial and well-known.

</div></div>

1) Not all the programs are using the same equations to compute the Air Density Ratio. Many programs are just based on simple models and simplifications. Granted, a good number of users won’t see the difference, but at LR it really matters.

2) Those “trivial” equations are really driving a lot of errors. The exact equations and model are far from being “trivial”

3) Having a single parameter to deal with, is obviously a more simple way than to deal with 3 or 4. Simple probability indicates less possibility of input error.

4) You’re right the exactness of the model is irrelevant to how carefully the atmospheric parameters are entered, but if they are correct, then the underlying model is vital. Otherwise, why to care for good input?

5) The difference of Sight-In conditions versus the actual Field Conditions is always there. A short ZR of say 100 yards, with a change of Air Pressure of just 2.0 inches and a slight temperature rise of 6 deg F will make a change in POI of 2.0 MOA at 1000 yards, creating a “parallel path curve”

6) Of course, some shooters might tend to think that a 2.0 MOA is of not enough consideration.
 
Re: Introducing "Shooter", ballistics for Android!

Sean;

I forgot about the call for the help section. I don't feel the need for any help other than the fact that I would need serious help to design a program that could do anything close to what you have here.
laugh.gif


On the decimal issue, it never occured to me to enter a decimal value. Smart to limit it though.

Thanks for planning to keep the alt measurement an option.
I don't plan to use it for ballistics calculations.
Correct me if I am wrong, but I always thought that taking a true current pressure reading negated the need for an altitude entry; thus saving me the concern for another variable so long as I keep the Alt entry at 0.

The logo looked fine to me...never paid it much mind.
laugh.gif


As to wind values. Huh?
They appear the same in the table as they do in the single-solution page. +/-
Maybe I am missing something?
 
Re: Introducing "Shooter", ballistics for Android!

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">1) Not all the programs are using the same equations to compute the Air Density Ratio. Many programs are just based on simple models and simplifications. Granted, a good number of users won’t see the difference, but at LR it really matters.

2) Those “trivial” equations are really driving a lot of errors. The exact equations and model are far from being “trivial”</div></div>

Well, they are probably not trivial to most shooters - but I'll guarantee you that they're trivial to the people who write the software. There is no mystery or magic about draq equations.

In any case, I'm not arguing for, nor do I use, ballistics programs based upon simplified models.

This discussion is about the importance, if any, of being able to enter environmental parameters as density altitude, about which all you can say is,

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Having a single parameter to deal with, is obviously a more simple way than to deal with 3 or 4. Simple probability indicates less possibility of input error.</div></div>

This is simply an attempt at Proof by Repeated Assertion.

Apparently you are willing to believe that people who are making long-distance shots with complex weapon systems are unable to correctly enter three parameters into a ballistic program, rather than one.

Personally, I have far more respect for the people we train in the art of shooting long distances than you do. Of course, I'm not trying to sell anyone on a particular ballistic program, which you appear to be.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">The difference of Sight-In conditions versus the actual Field Conditions is always there. A short ZR of say 100 yards, with a change of Air Pressure of just 2.0 inches and a slight temperature rise of 6 deg F will make a change in POI of 2.0 MOA at 1000 yards, creating a “parallel path curve”</div></div>

I'm afraid that turns out not to be the case. The POI on a thousand yard shot will in fact change by roughly that amount with that magnitude of change, but it's not because of a change in the short range zero. It's because of the difference in air density. All ballistic programs take that change into account.

Change in zero conditions matters for all practical purposes only when using extended-range zeros. If you're shooting a Barrett M82A1 with a 60 MOA base on it with a scope zeroed at 1000 yards, then yeah, you better take a change in zero-range conditions into account. That's not the case with a 100 yard zero.

In any case, both of the ballistic programs I use in the field allow for recording the air-data conditions for the zero range, and compensating for changes in them, at ranges where that might be useful.

My point in this discussion was that there is no need to use density altitude in a field ballistic program. Irrespective of the merits of any particular ballistic program, you have completely failed at trying to establish a need for that, except to avoid user input errors on three numbers rather than one.

I do not find that argument compelling, alas.
 
Re: Introducing "Shooter", ballistics for Android!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rafael</div><div class="ubbcode-body">As to wind values. Huh?
They appear the same in the table as they do in the single-solution page. +/-
Maybe I am missing something?

</div></div>
They shouldn't be....for example, type in 90 degree wind and you should see a neg correction for solution and over on the range table a positive.
 
Re: Introducing "Shooter", ballistics for Android!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rafael</div><div class="ubbcode-body">Yes, you are correct.
I suppose it really doesn't matter.
If you entered the wind condition, you should know which direction to correct.
laugh.gif
</div></div>
Yes of course, however that inconsistency between views is definitely bad and is fixed now (next release).
 
Re: Introducing "Shooter", ballistics for Android!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lindy</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">1) Not all the programs are using the same equations to compute the Air Density Ratio. Many programs are just based on simple models and simplifications. Granted, a good number of users won’t see the difference, but at LR it really matters.

2) Those “trivial” equations are really driving a lot of errors. The exact equations and model are far from being “trivial”</div></div>

Well, they are probably not trivial to most shooters - but I'll guarantee you that they're trivial to the people who write the software. There is no mystery or magic about draq equations.

In any case, I'm not arguing for, nor do I use, ballistics programs based upon simplified models.

This discussion is about the importance, if any, of being able to enter environmental parameters as density altitude, about which all you can say is,

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Having a single parameter to deal with, is obviously a more simple way than to deal with 3 or 4. Simple probability indicates less possibility of input error.</div></div>

This is simply an attempt at Proof by Repeated Assertion.

Apparently you are willing to believe that people who are making long-distance shots with complex weapon systems are unable to correctly enter three parameters into a ballistic program, rather than one.

Personally, I have far more respect for the people we train in the art of shooting long distances than you do. Of course, I'm not trying to sell anyone on a particular ballistic program, which you appear to be.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">The difference of Sight-In conditions versus the actual Field Conditions is always there. A short ZR of say 100 yards, with a change of Air Pressure of just 2.0 inches and a slight temperature rise of 6 deg F will make a change in POI of 2.0 MOA at 1000 yards, creating a “parallel path curve”</div></div>

I'm afraid that turns out not to be the case. The POI on a thousand yard shot will in fact change by roughly that amount with that magnitude of change, but it's not because of a change in the short range zero. It's because of the difference in air density. All ballistic programs take that change into account.

Change in zero conditions matters for all practical purposes only when using extended-range zeros. If you're shooting a Barrett M82A1 with a 60 MOA base on it with a scope zeroed at 1000 yards, then yeah, you better take a change in zero-range conditions into account. That's not the case with a 100 yard zero.

In any case, both of the ballistic programs I use in the field allow for recording the air-data conditions for the zero range, and compensating for changes in them, at ranges where that might be useful.

My point in this discussion was that there is no need to use density altitude in a field ballistic program. Irrespective of the merits of any particular ballistic program, you have completely failed at trying to establish a need for that, except to avoid user input errors on three numbers rather than one.

I do not find that argument compelling, alas.
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1) With all due respect, it seems to me you are not doing your homework.

2) The POI shift is caused by not accounting the difference in Sight-In versus Field Conditions. As simple as that…you can forever trying to say the other way around, but it’s there you like it or not. And to prove that just do some basic math.

3) That effect is very well known as “parallel path curve” for any serious ballistician. The net result if a shift of the TRUE Zero Range, as it wanders along the LOS line.

4) In Exterior Ballistics, that effect is perfectly explained by the principle of the “Envelope of Trajectories”, also take a look to the “Non-rigidity of trajectories”

5) If you don’t account for that, your program will yield two curves with the same ZR, which is WRONG. I mean when comparing a trajectory based on Sight-In conditions versus another one based on current Field Conditions.

6) Not trying to repeat myself, but it’s simple probability calculus that the stochastic probability of the input error of 1 parameter is about 85% less than when dealing with 3 or 4 parameters.

7) If you don’t like the use of DA on a mobile device, well, that’s your privilege. Others tend to think different.

8) Of course we can use (and I do) 3 or 4 parameters, that’s what not the point of the original post at all. Please do not deviate the subject.

9) The whole point is discussing LR situations, where a savvy shooter will try to account, as much as possible, for every possible source of error.

10) BTW, I’m not trying to establish nothing, as is your case, just sharing my thoughts and mathematical facts.
 
Re: Introducing "Shooter", ballistics for Android!

Both Eaglet and Lindy seem like smart folks in the mathematics department. Eaglet, if you can provide me with the math to apply a DA value to a ballistic coefficient, I'd be more than happy to work that into a future release.
 
Re: Introducing "Shooter", ballistics for Android!

Considering that the average .308 load zeroed at 100 yards has a flat trajectory from 70 yards from the muzzle to 109 yards, changes in short-range zero due to air density changes will be undetectable by the user.

The argument for zero range changes as a result of air density changes is, in fact, an argument that shooters should zero their rifles at extended ranges, record the conditions under which the zero was done, and then account for changes from those conditions in ballistic calculations.

Which practice will introduce more problems, and is not going to be done very often except by shooters who have no choice <span style="font-style: italic">except</span> to use extended-range zeroes.

I have two programs which allow for that practice. It's not an important feature.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">If you don’t like the use of DA on a mobile device, well, that’s your privilege. Others tend to think different.</div></div>

Here's the potential problem with the specification of DA in a ballistic program - air density is a function of barometric pressure, temperature, and humidity.

There are <span style="font-style: italic">many</span> combinations of those three variables which will produce the <span style="font-style: italic">same</span> density altitude.

However, muzzle velocity is <span style="font-weight: bold">also</span> a function of temperature - and <span style="font-weight: bold">only</span> of temperature.

So, a program which has environmental parameters entered as density altitude has no way of compensating for the change in muzzle velocity as a function of temperature - because it doesn't <span style="font-style: italic">know</span> what the air temperature is, it only knows the density altitude.

At least one such program which attempts to do temperature compensation of muzzle velocity assumes that the temperature at which the user is shooting is the ISA temperature for the DA entered by the user. <span style="font-style: italic">That assumption is almost always going to be wrong</span>, producing an erroneous calculation of muzzle velocity.

So, a program which has air-data entry as DA cannot also correctly compensate for changes in muzzle velocity with temperature - because it doesn't know the temperature.

A program which has air-data entry as temperature, pressure, and relative humidity, <span style="font-weight: bold">can</span> correct the muzzle velocity for temperature.

I consider <span style="font-style: italic">that</span> feature to be of far more importance to long-range accuracy than the possibility of incorrectly entering environmental parameters.

Without that feature, users must manually correct their muzzle velocity as a function of temperature, which introduces more possibility for error, if one is worried about that, and introduces another step in using the program in the field.

So, I prefer a program which features manual entry of the air-data parameters, and allows program correction of muzzle velocity as a function of temperature.
 
Re: Introducing "Shooter", ballistics for Android!

Sean;
One of my employees has an Archos 5 internet tablet.
He loaded Shooter on it and it ran just fine...as it should.

Nice big screen on that device.
Anyone not wanting to get an Android phone, but wanting to run Android apps, should take a look at this device.
It's about $250.00. It makes a very nice portable video player and web surfing device(Wireless access required) as well.
 
Re: Introducing "Shooter", ballistics for Android!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: seankndy</div><div class="ubbcode-body">Yeah some of them piss me off ;p The people that piss me off the most are the ones bitching about not having a "Help" section.
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Yea, I considered leaving a comment saying "if you need a tuitorial, you shouldn't be using the program."
 
Re: Introducing "Shooter", ballistics for Android!

Great app. So my question is about the ranging part of the app. When you put in the size of the target are you putting in the height or width? If you could do both that would be another nice feature.
 
Re: Introducing "Shooter", ballistics for Android!


<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: pjairfire</div><div class="ubbcode-body">Great app. So my question is about the ranging part of the app. When you put in the size of the target are you putting in the height or width? If you could do both that would be another nice feature.

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Think about that for a minute.
The answer is either. You can use the tool for any known dimension. The program doesn't need to differentiate between the two.
 
Re: Introducing "Shooter", ballistics for Android!

How hard would it be to have a feature where we can actually see a graph of the trajectory or wind drift, and possibly even graph more than one load on a graph so we can compare them visually?