I'm generating a drop chart for my long range load. Problem is I only have access to 250yrds to shoot and get actual bullet drop data to input into chart. Is this yardage ok or do I need to figure out a place to shoot farther to get mire accurate data? Thanks
- Thread starter emmagator
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Re: Trajectory validation
250 yards=unsatisfactory
If you, your ammo and your rifle were capable of 1-hole groups out to 250, you could kinda make it work, but even 1/4" @ 250 will make a large difference.
You'll have much better luck at longer range.
250 yards=unsatisfactory
If you, your ammo and your rifle were capable of 1-hole groups out to 250, you could kinda make it work, but even 1/4" @ 250 will make a large difference.
You'll have much better luck at longer range.
Re: Trajectory validation
You should true just before your bullet enters transonic flight. That speed will depend on the atmospheric conditions at the time of the test. Shooter or most programs will tell you the distance the speed of sound will occur for the given atmospheric inputs. I use a distance that the bullet will be traveling 100fps faster than the speed of sound. That will give you the most accurate validation.
250 is way to close. You will only validate for that speed/distance combination.
Check this out.
http://appliedballisticsllc.com/CH8_Addendum.pdf
You should true just before your bullet enters transonic flight. That speed will depend on the atmospheric conditions at the time of the test. Shooter or most programs will tell you the distance the speed of sound will occur for the given atmospheric inputs. I use a distance that the bullet will be traveling 100fps faster than the speed of sound. That will give you the most accurate validation.
250 is way to close. You will only validate for that speed/distance combination.
Check this out.
http://appliedballisticsllc.com/CH8_Addendum.pdf
Re: Trajectory validation
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Helidriver</div><div class="ubbcode-body">You should true just before your bullet enters transonic flight. That speed will depend on the atmospheric conditions at the time of the test. Shooter or most programs will tell you the distance the speed of sound will occur for the given atmospheric inputs. I use a distance that the bullet will be traveling 100fps faster than the speed of sound. That will give you the most accurate validation.
250 is way to close. You will only validate for that speed/distance combination.
Check this out.
http://appliedballisticsllc.com/CH8_Addendum.pdf </div></div>
The speed of sound is about 1130fps. So if i was to follow this method i would have to shoot out to 1400yrds????? Am i missing something here?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Helidriver</div><div class="ubbcode-body">You should true just before your bullet enters transonic flight. That speed will depend on the atmospheric conditions at the time of the test. Shooter or most programs will tell you the distance the speed of sound will occur for the given atmospheric inputs. I use a distance that the bullet will be traveling 100fps faster than the speed of sound. That will give you the most accurate validation.
250 is way to close. You will only validate for that speed/distance combination.
Check this out.
http://appliedballisticsllc.com/CH8_Addendum.pdf </div></div>
The speed of sound is about 1130fps. So if i was to follow this method i would have to shoot out to 1400yrds????? Am i missing something here?
Re: Trajectory validation
I've heard this as well.....that seems like a hell of a long ways out there, but what do I have to loose except a few rounds of ammo...
I've heard this as well.....that seems like a hell of a long ways out there, but what do I have to loose except a few rounds of ammo...
Re: Trajectory validation
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: coues7</div><div class="ubbcode-body">I've heard this as well.....that seems like a hell of a long ways out there, but what do I have to loose except a few rounds of ammo... </div></div>
But...but, but.....we're talking about long range here.
Long range = hell of a long ways out.
Again, just sayin'......
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: coues7</div><div class="ubbcode-body">I've heard this as well.....that seems like a hell of a long ways out there, but what do I have to loose except a few rounds of ammo... </div></div>
But...but, but.....we're talking about long range here.
Long range = hell of a long ways out.
Again, just sayin'......
Re: Trajectory validation
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: emmagator</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Helidriver</div><div class="ubbcode-body">You should true just before your bullet enters transonic flight. That speed will depend on the atmospheric conditions at the time of the test. Shooter or most programs will tell you the distance the speed of sound will occur for the given atmospheric inputs. I use a distance that the bullet will be traveling 100fps faster than the speed of sound. That will give you the most accurate validation.
250 is way to close. You will only validate for that speed/distance combination.
Check this out.
http://appliedballisticsllc.com/CH8_Addendum.pdf </div></div>
The speed of sound is about 1130fps. So if i was to follow this method i would have to shoot out to 1400yrds????? Am i missing something here? </div></div>
You got it......any other way and you are simply crossing 2 different curves. The actual trajectory and the predicted trajectory. If you true at 250 yards or even lets say at 800 yards all you are doing is manipulating either the velicoty or BC input data to arrive at the observed point of impact for that distance. If you true for 800 yards anything past that is again just a guess. It might be close but if you're talking "validation" close is not good enough. Look at the curves in the article from Brain Litz. It explains it pretty good.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: emmagator</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Helidriver</div><div class="ubbcode-body">You should true just before your bullet enters transonic flight. That speed will depend on the atmospheric conditions at the time of the test. Shooter or most programs will tell you the distance the speed of sound will occur for the given atmospheric inputs. I use a distance that the bullet will be traveling 100fps faster than the speed of sound. That will give you the most accurate validation.
250 is way to close. You will only validate for that speed/distance combination.
Check this out.
http://appliedballisticsllc.com/CH8_Addendum.pdf </div></div>
The speed of sound is about 1130fps. So if i was to follow this method i would have to shoot out to 1400yrds????? Am i missing something here? </div></div>
You got it......any other way and you are simply crossing 2 different curves. The actual trajectory and the predicted trajectory. If you true at 250 yards or even lets say at 800 yards all you are doing is manipulating either the velicoty or BC input data to arrive at the observed point of impact for that distance. If you true for 800 yards anything past that is again just a guess. It might be close but if you're talking "validation" close is not good enough. Look at the curves in the article from Brain Litz. It explains it pretty good.
