New Software Development Request

I sent an email to your LRH address 10 minutes ago
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Hello!

I can process right away. That means I send a copy of your order away to Gus who then sends you the email with download link from his site. Usually he does that within an hour or so.

To be sure I know when you order, call me right after.

920-379-2020
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Len Backus
Publisher
www.LongRangeHunting.com
Online Magazine & Forum
 
That's interesting about the Sierra program, Infintity isn't it, I have avoided it based on what others have said about older versions but maybe there are no longer concerns.
 
I sent an email to your LRH address 10 minutes ago
---------------------------------------------


Hello!

I can process right away. That means I send a copy of your order away to Gus who then sends you the email with download link from his site. Usually he does that within an hour or so.

To be sure I know when you order, call me right after.

920-379-2020
--
Len Backus
Publisher
LongRangeHunting Online Magazine and Forums
Online Magazine & Forum


Len---Done.

This is the header of the email confirmation I just got:

"LRH Gear Shop order successfully processed

Invoice:"


Thanks for the help!

DWM
 
As a pilot will tell you, the wind is stronger the higher you go. No friction with the ground and no obstacles to boil around.:D:D

Indeed, us pilots call it 'wind gradient' for the exact reasons you describe. You can really feel it when you take off from a cleared forest airstrip surrounded by tall trees. As you climb say 100ft above the tree line you could get as much as an extra 15mph of wind... It should be something to consider where your bullet flight is in a particular environment where this is prevalent.

Mikecr said:
In the context of wind's contribution toward drift, I'm pretty sure you got it backwards. Although, I'd have to look around a bit to find supporting evidence.
Drift occurs with a bullet's slowing. If the bullet did not slow from the muzzle to the target, no amount of wind would cause drift. So a wind value is applied to the time of flight difference between a bullet that hypothetically doesn't slow, and your actual time of flight. This slowing occurs at the highest rate nearest the muzzle.
For example;
In space a bullet might take 0.50 seconds to travel 1kyds.
In our atmosphere, it might take 1.00 seconds.
Any wind would apply to that 1/2sec of TOF difference.
And by far, most of that difference occurs nearest the muzzle, as a bullet slows relatively little, further downrange.
This passes test w/regard to the mechanics of drift, which holds that base drag pulls a bullet downwind while it's nose is pointing into wind.
This base drag would be highest at the highest velocity, and affect a bullet's direction earlier and therefore longer during travel.

Many point to the apparent increasing moa of drift with distance, to support a notion that drift has an increasing rate downrange, and so downrange wind must be a bigger factor.
But demonstrated drift could not be easily quantified in moa, as nothing here is linear.
It can't be suggested that 1" of drift printing at 100yds is ~1moa, because much of that deviation may have occurred between 90yds-100yds. So it could be & print 8moa further downrange, even with no wind contributing beyond 100yds. That is, if 0.8" of that 1" deviation occurred in the 10yds between 90-100.
Seems like alot for a bullet to 'steer' so fast, but consider 1kyd drifts. They don't correlate to wind speed at all.

Anyway, I'm thinkin out loud I guess.
Pretty sure near wind is a bigger factor than far wind.

Mikecr, take a 1200yd shot for example... using my .308 and using my ballistic calc, my bullet flys thru the first 400yds in approx 0.49 secsonds.

From 400yds - 800yds, the same bullets takes 0.65 seconds for this middle leg.

And the last part of its flight from 800 - 1200yds, it spends a whopping 0.90 seconds. Total flight time = 2.04 seconds.

So it takes almost twice the time to complete the last 1/3 of its flight compared the the first 1/3. This means whatever wind is present during the last 1/3 has almost twice the time to apply its vector and drift acceleration on the bullet.

Furthermore, as the bullet slows down its BC decreases, so in the last part of its flight it not only has to be effected by the wind for longer but the wind can push it more easily due to a lower BC.
 
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Mikecr, take a 1200yd shot for example... using my .308 and using my ballistic calc, my bullet flys thru the first 400yds in approx 0.49 secsonds.

From 400yds - 800yds, the same bullets takes 0.65 seconds for this middle leg.

And the last part of its flight from 800 - 1200yds, it spends a whopping 0.90 seconds. Total flight time = 2.04 seconds.

So it takes almost twice the time to complete the last 1/3 of its flight compared the the first 1/3. This means whatever wind is present during the last 1/3 has almost twice the time to apply its vector and drift acceleration on the bullet.

Furthermore, as the bullet slows down its BC decreases, so in the last part of its flight it not only has to be effected by the wind for longer but the wind can push it more easily due to a lower BC.

Ok, a few problems with this argument;
1. It's probably better for another thread
2. Wind doesn't 'push' bullets anymore than rain 'wettens' bullets. With this, wind calculations are not based on TOF, but instead on TIME LAG. And these calcs can be performed from yard to yard as well as muzzle to target. YOUR argument suggests that very heavy bullets would drift more in a given wind because their TOF is higher due to lower MV. This is not true -because their lag time is lower, because their BC is higher. Heavy higher BC bullets, launched slower, drift LESS given enough range to demonstrate. And the majority of their drift(in moa) still occurs right where lag time is highest(nearest the muzzle).
3. Actual BC does not decrease as a bullet slows.
The changes in BC you notice result only with comparing actual/local drag coefficients to G1 or G7 standard drag coefficients. This is neccessary for software that makes this comparison. Not so with software that doesn't. I assure you, with your bullet's ACTUAL drag curve referenced by your software, BC would remain constant with velocity. Pejsa manages this feat with a coefficient adjustment.
As well I'll assure you that drag itself decreases with dropping velocity.
 
Mikecr, would you start a thread to flesh this out in, I'm dying to grill you guys about this but it seems it needs a new thread. So much good stuff get lost in pages 5,6,7 in a thread because they are rabbit trail, but new guys are looking for info and it would be easy to find in a new thread.
 
3 different wind brackets means little unless you have an anemometer in 3 different locations, and even this means nothing unless the wind is constant.... instead of making one guess, your simply making 3 guesses...

the last 1/3 of the trajectory is by far the most important and is the part you can never measure, you are required to guess. This is why i dont own a kestrel, measuring the wind where your shooting from doesnt help me... I have far more success via reading the terrain, guessing the wind by observation, and practice practice practice. Gadgets and software wont help you here...

groper,

This is a good video tip.

YouTube - botwtv's Channel
 
1. im fine with another thread, until then it stays here.

2. when its windy, my bullets get pushed. When it rains, my *** gets wet. I dont understand what your saying here?

The wind imparts a vector on your flying bullet same as wind imparts a vector on my aircraft when i travel from one airfield to the next. gravity imparts a vector on it in the same way also. There are 3 parts to these vectors... direction, force, and time. When i say time, this is the amount of time the force is applied. so in the case of windage the time the bullet spends in horizontally moving air not including any time of its journey spent in still air. With gravity, its the entire time of flight obviously.

3. What is time lag? ill take a guess and say that perhaps you are referring to INERTIA? In that, it takes more force to accelerate a heavier bullet than a lighter one, everything else being equal. Thus a heavier bullet drifts less in the wind. i totally agree with this, but heres the thing.... what happens when you have 2 bullets with the same WEIGHT, but one has a much higher BC than the other? Which one drifts more or less and why? Obviously, it has to do with the form of the bullet not just its mass.

I still dont see your point with regard to time lag???
 
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