another thought problem, NOT gun related

BillBrawand said:
[QUOTE WHEN YOU GET TO THE RANGE YOU BETTER LOOK CLOSER.=alinwa;846243]the wind drift lift thing...... here's another chart often used in Bench Rest circles. Which I completely disagree with, it's as warped as the first one I posted... the headwind/tailwind illustrations are clearly not reasonable, obviously extrapolated in innernet shooters' wet dreams VS supported by physics and real-world data.

((((think, people.... THINK!! Unsupported opinions and guesses have far too much sway in this world.... THINK about a "10mph headwind blowing the bullet down on the target" and then think about your ES..... if you shoot a median velocity of 3200 but your loading techniques yield velocities ranging from 3190 to 3210 for 20fps ES then in your group is effectively a 10mph headwind and a 10mph tailwind...... and the number of people who can load to under 20fps ES is a fraction of a fraction of a fraction of a percent of the reloaders on thee earth))))

View attachment 24849

And here's a third one which, while I STILL don't find it accurate it's better than the others :) it makes it too freakin' easy, but it at least understands that head and tailwinds ain't in it! This alone is enormously informative.

View attachment 24850

3 charts, all having adherents yet all three showing radically different wind effects. I happen to have experienced and documented a different thing, similar to chart #3 but not a planar line. This is where Gene Beggs' info/data/experimentation with wind probes and the cumulative effect of wind vector on a 3-D object is useful.
Click to expand...
[/QUOTE]

But does this only apply to right hand twist barrels? Would a left hand twist reverse the rules? More to ponder on.
 

But Bill, a bullet blown to the left will also rise above the aiming point while a bullet blown to the right will impact low :)[/QUOTE] ONLY IF ITS DIAGONAL.
 

But does this only apply to right hand twist barrels? Would a left hand twist reverse the rules? More to ponder on.[/QUOTE]

yes
 
alinwa said:
some times depends what wht part of range you are on.
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only if wind comes over or under the flaigs do you get high or low with diagonal.

Actually Bill, it happens on any range at any point on the range. A bullet "blown" to the left will always rise and a bullet "blown" to the right will always fall. It's the same mechanism as "spindrift" although few people ever connect the two, including our current crop of so-called "professional ballisticians" in the world.

LOL, lotta' "quotes" in there cuz a lotta' disagreement on the verbiage...... kinda' like my use of "catch a balloon" to illustrate a point. Words just tend to set certain folks' teeth on edge.

Rush said "words mean things"

50% of the population says "words are mean things"

Here's a diagram to illustrate the wind-rise effect

View attachment 24848

LOL, this guy calls it "vector wind effect"...... which clearly illustrates that even though he SEES it, he has no idea from whence it comes, what drives it nor how it works........ :)[/QUOTE]
 
[QUOTEYOUR RIGHT BUT ONLY AS I DESCRIBE IT.=BillBrawand;846266]only if wind comes over or under the flaigs do you get high or low with diagonal.

Actually Bill, it happens on any range at any point on the range. A bullet "blown" to the left will always rise and a bullet "blown" to the right will always fall. It's the same mechanism as "spindrift" although few people ever connect the two, including our current crop of so-called "professional ballisticians" in the world.

LOL, lotta' "quotes" in there cuz a lotta' disagreement on the verbiage...... kinda' like my use of "catch a balloon" to illustrate a point. Words just tend to set certain folks' teeth on edge.

Rush said "words mean things"

50% of the population says "words are mean things"

Here's a diagram to illustrate the wind-rise effect

View attachment 24848

LOL, this guy calls it "vector wind effect"...... which clearly illustrates that even though he SEES it, he has no idea from whence it comes, what drives it nor how it works........ :)[/QUOTE][/QUOTE]
 
MilGunsmith said:
But does this only apply to right hand twist barrels? Would a left hand twist reverse the rules? More to ponder on.
Click to expand...


so when I was much younger and more theoretical and once I understood that the Coriolis Effect is ALWAYS to the right where I shoot, regardless of direction.....I called some cut-rifling barrel makers about making some left-twist barrels because on paper I could use Coriolis to counteract spin drift in the northern hemisphere (you'se Ozzies get to cheat, right hand twist does counter Coriolis Dow'nunder)

As per usual I got laffed outa' town

Then I started shooting long range and realized I was misguided, losing a dollar chasing a dime.... actually worse, spending dollars and getting abso-friggin-lutely NOTHING in return. I still spend dollars for 1/10moa and consider it well spent, but Coriolis and spin drift ain't worth NUTTIN'!! And the number of folks who believe it's affecting them, and don't even have a level on their rifle is staggering.... BTDTGTTS

My brother in law and myself were convinced at one time that we'd actually witnessed spin drift shooting down off a hillside when the wishes were just hanging in the air, but whether we did or not is completely immaterial to me now, when I actually CAN dial a grapefruit at 1376 yds I realize that spin drift, Coriolis, Eotvos, gravitational anomolies and Magnus's are keyboard effects, not things that'll help me hit stuff.

But lift at 100/200 is a spindrift that DOES affect my holds ;)
 
Gyroscopic Precession

Just to throw another hat in the ring.

Could not Gyroscopic Precession https://science.howstuffworks.com/gyroscope.htm be a reason for the deviation of a projectile when displaced by an external force?

After all, our projectiles are spinning just like a gyroscope. Imagine that they are just like a spinning top with the point facing towards the target.

When an external force (wind in the context of this discussion) attempts to displace our spinning projectile sideways, the resultant deviation is actually at 90° to the applied force.

This raises a few interesting points:

The deviation is dependent upon the magnitude of the applied force (wind velocity).
The deviation is dependent upon the rate of spin (rifling twist).
The direction of the deviation is dependent upon the direction of spin and the axis that the displacing force is applied to.

Also maybe why a barrel and projectile with the minimum twist rate (to stabilise the projectile) are considered to be the most accurate.

Anyhow, that's my 5¢ worth and I only included it as I have never seen this aspect discussed before.


Regards * doggie *
 
doghunter said:
Just to throw another hat in the ring.

Could not Gyroscopic Precession https://science.howstuffworks.com/gyroscope.htm be a reason for the deviation of a projectile when displaced by an external force?

After all, our projectiles are spinning just like a gyroscope. Imagine that they are just like a spinning top with the point facing towards the target.

When an external force (wind in the context of this discussion) attempts to displace our spinning projectile sideways, the resultant deviation is actually at 90° to the applied force.

This raises a few interesting points:

The deviation is dependent upon the magnitude of the applied force (wind velocity).
The deviation is dependent upon the rate of spin (rifling twist).
The direction of the deviation is dependent upon the direction of spin and the axis that the displacing force is applied to.

Also maybe why a barrel and projectile with the minimum twist rate (to stabilise the projectile) are considered to be the most accurate.

Anyhow, that's my 5¢ worth and I only included it as I have never seen this aspect discussed before.


Regards * doggie *
Click to expand...

Yes.

Gene Beggs did some interesting experiments in this regard back in the days (months) (years) we spent trying to understand bullet flight.

here, in no particular order are some threads from then;
http://benchrest.com/showthread.php?91377-bullet-above-bore-s-axis
http://benchrest.com/showthread.php?65263-Attention-all-ballisticians
http://benchrest.com/showthread.php?64966-For-you-ballisticians

And I won't even include The Mother Of All Wind Drift Threads in the interest of brevity ;) (I think it went 141 posts)
 
doghunter said:
Just to throw another hat in the ring.

Could not Gyroscopic Precession https://science.howstuffworks.com/gyroscope.htm be a reason for the deviation of a projectile when displaced by an external force?

After all, our projectiles are spinning just like a gyroscope. Imagine that they are just like a spinning top with the point facing towards the target.

When an external force (wind in the context of this discussion) attempts to displace our spinning projectile sideways, the resultant deviation is actually at 90° to the applied force.

This raises a few interesting points:

The deviation is dependent upon the magnitude of the applied force (wind velocity).
The deviation is dependent upon the rate of spin (rifling twist).
The direction of the deviation is dependent upon the direction of spin and the axis that the displacing force is applied to.

Also maybe why a barrel and projectile with the minimum twist rate (to stabilise the projectile) are considered to be the most accurate.

Anyhow, that's my 5¢ worth and I only included it as I have never seen this aspect discussed before.


Regards * doggie *
Click to expand...

Finally! Also left hand twist will be opposite of right hand twist. Look at a swash plate on a helicopter.
Bill
 
Finally……
Someone who has more free time than the hard working concrete man from Washington…State, that is.
splain to me the Americas Cup boats doing 29 knots downwind while the wind speed was recorded as 8.8 knots.
Good day. I’m done. Wallow in your stubbornness.
 
Francis, Its a miracle

FBecigneul said:
Finally……
Someone who has more free time than the hard working concrete man from Washington…State, that is.
splain to me the Americas Cup boats doing 29 knots downwind while the wind speed was recorded as 8.8 knots.
Good day. I’m done. Wallow in your stubbornness.
Click to expand...
Kinda like that shot came thru the target the wrong way down at Mickeys. If my memory serves, it was your brothers target
 
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