From another thread that started as a total other subject! Are our bullets pushed by the wind or what and what is more important and has more effect in regard to reading the wind, wind at the shooter or close to the target? Lag time vs Time of Flight? Hopefully I don't breach some internet forum protocol doing this!
The starting thread New Software Development Request
the questions start in pages 4-5.
Join Date: Aug 2003
Re: New Software Development Request
Originally Posted by groper
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.
Join Date: Sep 2008
Re: New Software Development Request
1. im fine with another thread, until then it stays here.
2. when its windy, my bullets get pushed. When it rains, my ass 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???