Hey fellas, I'm new to the forum and just thought I'd pick your brains a bit. I would like to hear your opinions on the various ballistics programs that are out there. I've got the rifle,range finder, and some accurate hand loads. The last thing I need to get is a shooting chrony. If all the correct data is entered into the program, will the program get me in the ballpark or would I be better off setting targets out at various ranges and go through that lengthy process? I want to make a very accurate ballistics chart, so when I dial in come up clicks I know I'm going to hit what I'm aiming at. Your thoughts and opinions would be very appreciated.
ballistic progam accuracy
- Thread starter coyote32
- Start date
There are some good programs out there like the one by sierra that should get you close, however in my opinion you actually have to get out to the range and shoot at various ranges to make a truly accurate dope chart.
I use this ballistics program because its absolutley free http://www.eskimo.com/~jbm/calculations/traj/traj.html
You definetly need to check your drop chart, by actually shooting. But remember all that can change with different temperatures and elevations that you shoot in.
I also use increments of 25 yards when setting up a chart for long range. Alot of experienced long range shooters use a palm pilot with exbal, I don't have the money for all these cool toys.
You definetly need to check your drop chart, by actually shooting. But remember all that can change with different temperatures and elevations that you shoot in.
I also use increments of 25 yards when setting up a chart for long range. Alot of experienced long range shooters use a palm pilot with exbal, I don't have the money for all these cool toys.
Yes keeping good records is the key. I have a separate note book for each one of my rifles. I record the temp, humidity, wind speed and direction, if a maid any changes in wind or elevation on the scope, the group that I shot, the range and angle of the shot, the ammo that I used and other various weather conditions. Then you will be able to look back on this stuff and know the proper dope for your scope.
I have a Pact Chronograph with the ballistic program. The ballistic program is typical of others that are available from some of the bullet manufatures. The pact program has a library for the ballistic coefficient which is a critical data component that is needed to calculate moa settings. The program works! It will get you on target but you have to adjust for other enviromental varibles. Use the ballistic calculations from a program and coordinate with your field testing at the range. You are going in the right direction.
CatShooter
mrjdasr said:
That would be a G7.
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G1 is the model made for flatbased bullets, G7 is for modern vld type bullets, but everytime I play with G7 everything is out of whack.. DO you have to use a different number for ballistic coefficent-or use the same BC as G1, ex .556?
Note: I read a post on BR Central about this,what I tried to explain), I'll Dig it up when I get time.
Note: I read a post on BR Central about this,what I tried to explain), I'll Dig it up when I get time.
CatShooter
Flybuster said:
Virtually all bullet makers use G1 numbers, regardless of the bullet style.
Obviously, a 180 grain flat base will not fly the same as a 180 grain VLD at long range.
At short range, it makes no difference, as the total diameter of the bullet body is in vacuum at the base, but as the bullet slows down and the airflow starts to roll around the base, the tail shape comes into play, and the long boat-tails start to do their stuff, and the bullet gets its legs.
Most bullet makers do NOT test their bullets at long range, they use velocity loss between two traps 100 to 200 yds apart - under these conditions, all bullets will give losses that are equivalent to G1, so the makers assign G1 numbers.
Another reason is that G5 and G7 numbers are actually smaller,G5 and G7 use different formulas), so it is like advertising... bigger numbers sell, it doesn't matter if they don't mean anything.
For example... for a 30 cal 210 VLD, the G1 BC @ 3,000 fps is 0.710
The G5 number is 0.432
The G7 number is 0.350
All for the same bullet!!!
So which would you buy if you were looking for a 210 VLD
Charlie's bullets, a 210 VLD with a G1 BC of 0.710
Freddy's bullets, a 210 VLD with a G5 BC or 0.432
or
Tommy's Bullets, a 210 VLD with a G7 BC of 0.350.
Even though Tommy's bullet's gives you the true G7 BC, he will be on welfare in 6 months, and Charlie's crew will be working double shifts and Sundays!
Plus, to make it worser, the companies do not use the same programs and/or procedures to derive the G1 BC's so Sierra's 0.400 is not equal to Hornady's 0.400.. Hornady's numbers are usually lower than Sierra's, but the bullets fly flatter at the same MV.
Go Figure
.
CatShooter
mrjdasr said:
The "G" numbers represent shapes - and they were assigned to small and medium bore artillery shells with bore diameters of 2" to ~5" inches.
Each new artillery shell design was tested and assigned a new "G" number for that family of designs.
Part of the problem is that none of the classical programs were effective for bullets under 1", though some of the newer ones are very accurate.
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I just read that post at BR central http://benchrest.com/forums/showthread.php?t=51628&highlight=g-7
It's saying the same thing Catshooter said.
But, the reason I use G-1 formula is because thats what Berger gives me, a G-1 ballistic coeffiecent.
I would definetly use G-7 if I knew the G-7 B.C. for my Berger 105 VLD.
It's saying the same thing Catshooter said.
But, the reason I use G-1 formula is because thats what Berger gives me, a G-1 ballistic coeffiecent.
I would definetly use G-7 if I knew the G-7 B.C. for my Berger 105 VLD.
CatShooter
Flybuster said:
Fly...
The G7 BC for the Berger 6mm 105 VLD is 0.265
If you want me to run some numbers for you, give me the MV and atmospherics - I can run G7 BCs.
.
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Catshooter, I would be interested to know what you do for a living. As far as I can tell you are the most knowledgeable poster on this forum. So, it makes me curious how you obtained all this great info?!?!
CatShooter
blacknwhite said:
HA!...
There are a bunch of guys here that think I'm a flaming Idjit!
Meow
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