Is faster always better in the wind? New slug info page3

[tor47]

Pretty plain and simple here's some calculations straight from Chairgun

I am not an expert but BC might not be the same for thouse 2 calculations. It will probably be a litle lower for the fastest speed

 

[FredAZ]

Turn OFF the wind and note the drift caused by spin which is different at the different velocities.

Turn ON the wind and compare the DIFFERENCE the wind makes over the drift observed above.

Calculate the wind's contribution to the drift.

Let's see FOUR [giant] screen captures [of whatever app you believe is the true repository of ballistics.]

 

[tor47]

Pretty plain and simple here's some calculations straight from Chairgun

I am not an expert but BC might not be the same for thouse 2 calculations. It will probably be a litle lower for the fastest speed

To be honest I read it wrong first time. I see now the drift is wider on the fastest speed

 

[Centercut]

I gotta hand it to you Fred. You’re a non/believer in the face of Math and Physics proof. Plus real world trials to confirm that proof. Yet you still stick to your “logic”. Gotta admire that. There were those that stuck to the world is flat theory even after men sailed around the world... FYI, spin drift affects about 0.1 Mil at 100 yards with a typical pellet. Not enough to make a difference...

 

[FredAZ]

No - just not a person who believes anything that comes from an app is right.

Do us a favor and stay away from Mach.

Give us screen shots of a fixed wind and velocity steps of 500ft/sec, 600ft/sec, 700ft/sec and 800ft/sec. changing nothing but velocity.

When I run Chairgun, I get the following results for drifts at a set velocity. Drifts are at 40 and 80 yards in inches:

500 ft/sec = 5.1 & 22.6

600ft/sec = 4.2 & 18.3

700ft/sec = 3.7 & 15.7

800ft/sec = 3.4 & 14.4

900ft/sec = 3.4 & 14.0

1000ft/sec = 3.7 & 14.3

So - until you get to MACH where the drag model craps out, drift is proportional to time of flight and inversely proportional to muzzle velocity.

 

[Centercut]

Looks like you just proved 850 to 950 FPS is the sweet spot. Thanks!

No one shoots PCPs under 800 FPS, at least none that I know. So tell me, why is your wind drift at 1000 FPS more than it is at 900 FPS? Things that make you go hmmm...

Mach is about 1130 FPS by the way...

 

[tor47]

Your drift calculations will probably be worse than you previous calculated. The reason is you use a Constant BC. BC for pellets might be worse at 1000fps, than 800.

 

[18.13]

 

[Centercut]

Here you go Fred. From Strelok Pro, .25 JSB King, .038 BC. 10 mph wind at 90 degrees. It’s easy to see that 850 to 950 FPS is the sweet spot. And at 850 there is less wind drift than at both 1000 and 1050 FPS. Weird, huh? At 800 FPS, there is less wind drift than at 1000 FPS, despite the fact that it’s going 20% slower and spending 20% more time in the wind. We’ll convince you sooner or later that the world isn’t flat...

800 FPS 

850 Fps

900 FPS 

950 FPS 

1000 FPS

1050 FPS

 

[18.13]

From Hard Air Mag

https://hardairmagazine.com/ham-columns/the-external-ballistics-of-diabolo-pellets/

 

[FredAZ]

The transonic region spans mach by well over 100fts depending on you particular projectile.

Look at a drag curve over velocity and you'll it it's very non-linear in the transonic region - stay in the linear region and the behavior is obvious.

The peak of the drag curve is centered at Mach-1 and the skirts are broad - as you climb the "mountain" to mach, stuff happens.



So - drift is indeed proportional to drag which goes off the charts for SOME velocities.

You need to find the knee in the drag curve for the pellet shape you are shooting under the current atmospherics to optimize wind effects.

 

[Centercut]

Oh snap! Wait, did you just say we all are correct and drift ISN'T proportional to the time of flight? So you’re saying science is right and your other posts were wrong? Yes, drift is proportional to drag which is defined by BC. Finally... Another science denier bites the dust.

 

[FredAZ]

Drift is proportional to drag AND time of flight.

Time of flight is linear, drag is not.



So no snap.

 

[Centercut]

I’m done. Some people, despite incontrovertible proof to the contrary, will believe whatever makes them feel better...

Don't fear the science. Get over your fear and embrace the science! 

Take care Fred. It’s been fun...

 

[Dairyboy]

Not sure why it's so hard to believe for some people but alright! Im with you Mike!

 

[Centercut]

Not sure why it's so hard to believe for some people but alright! Im with you Mike!

I know, right? You know the horse is damn thirsty, so you lead him to the water, show him the water, push his face into the water, but he still refuses to drink...

 

[mtnGhost]

Drift is proportional to drag AND time of flight.

Time of flight is linear, drag is not.



So no snap.

Drift is influenced by drag not time. Time is a measurement dimension.

 

[Centercut]

Time of flight is linear, drag is not.

Ghost, there are so many total gross conceptual errors with the above statement, physically and mathematically, that I decided to leave it alone... 

 

[mtnGhost]

Time of flight is linear, drag is not.

Ghost, there are so many total gross conceptual errors with the above statement, physically and mathematically, that I decided to leave it alone...

Those flat earther's like their football bats CC!

 

[Smitty911]

Great info!

What's also interesting is look at how much faster the higher speeds sheds there fps proving the BC suffers in that transonic zone. Starting off with a 150fps "head start" it's down to only 60fps by the time it reaches 100yds. At only 900fps the fps loss is 290fps while at 1050fps the fps loss is 380fps.

I believe the from my Glider Flying lessons that one of the instructors said "parasite drag increases with the square of speed. (i.e. double the speed and parasite drag increases four times.)"

Just another factor.



Smitty