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Quest for g7 ballistics programs (can we please make a list)

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  #36  
Unread 08-25-2009, 10:48 AM
JRu JRu is offline
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Re: Quest for g7 ballistics programs (can we please make a list)

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First, what do you mean by: "...all J2ME ( CLDC 1.1 MIDP 2.0 , if I recall correctly ) enabled phones..."?

Would your program also work on PDA's/PPC's?
As far as I know, Java Mobile Edition (J2ME) is extremely widespread on GSM cell phones, smart phones, PDA/PPCs, mini laptops etc. I know some Java Virtual Machine (JVM) implementation exists for pretty much anything that can be programmed... I'm fairly confident pretty much every basic cell phone nowadays supports J2ME, if for nothing else, at least because of support for games.

Simply put, if you have a Tetris- clone or a simple space shooter in your phone, there's a good chance it will run this ballistics software. Nokia, Sony Ericsson, Samsung, HTC, Motorola... All have Java implementations and I've run this software on some very simple devices. I specifically did NOT want to make it a Symbian- only or iPhone- only. Naturally it will run on every Blackberry, iPhone and Nokia out there, as these are the more powerful phones.

Quote:
What type of solver does your program use? From the sounds of it, you're using the Pejsa formulas.
Yep, we can hardly keep it a secret as the BC+"K" ( or whatever you decide to call the retardation coefficient) is a dead giveaway if you happen to be familiar with Pejsa. There's no tricks to it, it's just plain old hard work making something known ( the Pejsa formulas) into a complete product with save/load/rename/sort configurations, gathering all needed formulas into one place and wrapping it into something that doesn't throw an exception every time you enter a letter when it's expecting a number...

I was using Shawn's "spin drift as a wind function" but now I'm implementing your stability factor based formula. I already implemented your Coriolis drift, both horizontal and vertical. J2ME math library doesn't even have an exponent/non-integer power functions but we have good approximation algorithms -- in fact, we manage with just mul/div/sub/add so this thing could basically be integrated into a wristwatch if need be...
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  #37  
Unread 08-25-2009, 11:28 AM
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Re: Quest for g7 ballistics programs (can we please make a list)

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Originally Posted by JRu View Post
Guys, I'm really, REALLY, trying to complete and release the 1.0 version of our software
What software?
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  #38  
Unread 08-25-2009, 12:01 PM
JRu JRu is offline
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Re: Quest for g7 ballistics programs (can we please make a list)

Our mobile ballistic software that isn't based on G7 but gives comparable results. Work-in-progress but very close to completion -- only delayed by the fact that I need to work on cancer treatment software during office hours
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  #39  
Unread 08-25-2009, 04:41 PM
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Re: Quest for g7 ballistics programs (can we please make a list)

The problem with the Pejsa system is you have to do extensive downrange testing to establish the retardation coefficient and break velocity to get it to match your actual trajectory. Yes, once you've done that, it will get pretty close out to transonic velocities.
The only system that I've found so far that can be used from the get-go with a single input is the G7 BC. It is also the only one that can be used for comparisons between bullets, as with Pejsa, you have these 2 other factors plus the G1 BC that have to be fudged that make comparisons inaccurate.
An averaged G1 works ok to about 2000 fps or around 1000 yards with fast VLD's, a best guess Pejsa will work to a bit further, but beyond that you need to adjust with multiple BC's for G1, or retardation coefficients and break velocities for pejsa - both from actual shooting tests to have any success.
G7 is it - at this stage anyway!
Greg
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  #40  
Unread 08-26-2009, 12:11 AM
JRu JRu is offline
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Re: Quest for g7 ballistics programs (can we please make a list)

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The problem with the Pejsa system is you have to do extensive downrange testing
If all you have is a G1 BC then yes, finding the optimal values will require gathering velocity and/or drop data, but if you can provide us a G7 BC, you already have a very good approximation of the actual data and corresponding G1 & retardation coefficient can be solved numerically. Naturally the process can be reversed to achieve G7 BC numbers for comparison.

This is exactly the same thing we've done versus radar data, and the 338LM flight path predicted by our solver is within 0.07 MOA of error up to over 1500 yards.

"G1 BC+K flight path" , "radar data" ( actual flight path ) and "G7 BC flight path" are interchangeable to very fine accuracy, so converting between them is just the matter of solving the key values for minimum error. "Single G1 BC flight path" can't reprocude the same shape of flight path the others can, so it cannot be accurately converted.
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  #41  
Unread 09-05-2009, 08:24 PM
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Re: Quest for g7 ballistics programs (can we please make a list)

JRu,
How's that Mobile Ballistics Program coming? I am currently at the point of acquiring a ballistic program to put on my pocket PC and as you might imagine, the selection is tough. especially in light of the trend toward the use of the G7 BC's.

Should I wait awhile longer or should I go ahead with something like Loadbase? thanks for the effort and any advice regarding my decision.
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  #42  
Unread 09-05-2009, 10:03 PM
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Re: Quest for g7 ballistics programs (can we please make a list)

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Originally Posted by Chief1942 View Post
Should I wait awhile longer or should I go ahead with something like Loadbase? thanks for the effort and any advice regarding my decision.
Check this out and see what you think. Link--> Gus is a man of his word. Guess what LB 3B mobile has now?
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