Trans-sonic and wind drift

[Shannow]

Originally Posted By: billt460
Then how can you possibly not know a .22 Magnum drifts less than a .22 L.R. at 100 yards?


Firstly, because facts are as I've demonstrated (and every reputable ballistics calculator will tell you), in the range 1,000 to 2,000 fps that for two identical projectiles, the 1,000fps projectile will have less drift...period...if you've got a better BC in the magnum, it's drift will improve...but put that same bullet at 1,000fps, and it will be better too.

Secondly, ad in line with the first point, 15 years in the rimfire club, and I never met a person whose scores didn't improve when I convinced them to drop high and hyper velocity .22s and go back to standards...you see, they were fixated on time of flight, not wat actually happens.

Thirdly, in that same period I NEVER saw a decent score shot with a Magnum. The proponents of the cartridge at the smallbore range tended to be loud (noisy rifles, noisy owners) poseurs.

Originally Posted By: billt460
By his own admission he shoots little to no .22 L.R. or Magnum. And has no use for the caliber itself.


Where did you get this "own admission" from ?

Making up fibs to improve your position is really poor form, wouldn't you agree ?

 

[ZeeOSix]

Originally Posted By: Shannow
Originally Posted By: billt460
Then how can you possibly not know a .22 Magnum drifts less than a .22 L.R. at 100 yards?


Firstly, because facts are as I've demonstrated (and every reputable ballistics calculator will tell you), in the range 1,000 to 2,000 fps that for two identical projectiles, the 1,000fps projectile will have less drift...period...if you've got a better BC in the magnum, it's drift will improve...but put that same bullet at 1,000fps, and it will be better too.


Using this Hornady ballistics calculator, it always shows that the same exact bullet with every variable held constant but the muzzle velocity will always show that the faster bullet will have less wind drift.

Use the "Advanced" mode (upper RH corner pull down) of the calculator to enter wind speed and angle.
http://www.hornady.com/ballistics-resource/ballistics-calculator

 

[Shannow]

Originally Posted By: ZeeOSix
Originally Posted By: Shannow
Originally Posted By: billt460
Then how can you possibly not know a .22 Magnum drifts less than a .22 L.R. at 100 yards?


Firstly, because facts are as I've demonstrated (and every reputable ballistics calculator will tell you), in the range 1,000 to 2,000 fps that for two identical projectiles, the 1,000fps projectile will have less drift...period...if you've got a better BC in the magnum, it's drift will improve...but put that same bullet at 1,000fps, and it will be better too.


Using this Hornady ballistics calculator, it always shows that the same exact bullet with every variable held constant but the muzzle velocity will always show that the faster bullet will have less wind drift.

Use the "Advanced" mode (upper RH corner pull down) of the calculator to enter wind speed and angle.
http://www.hornady.com/ballistics-resource/ballistics-calculator


Try it again...in the trans-sonic region, which, coincidentally is the title of the thread, and check which ballistics calculator that I used...

Originally Posted By: Shannow
Problem is comparing apples to apples in the trans-sonic region.

Spend some time with
http://www.hornady.com/ballistics-resource/ballistics-calculator

And alter only one variable at a time...the subject was .22s, and the .223 vesus .22-250 was brought in...it's valid, but bear with me...the difficulties, and the counterintuitive effects are all at the transsonic region, when a subsonic bullet takes longer to get there but is "Delayed" less by it's lower drag co-efficient than it's supersonic counterparts.

Pick a B.C. of 0.13 (not good, but rimfire typical), and 10MPH cross wind
Code:


Velocity 100Y 200Y

1000 4" 15"

1200 5.4 19

1400 6.0 21.8

1600 5.7 22.4

1800 5.1 21.6

2000 4.5 19.9

.

.

3200 2.3 10.4

3600 2.0 8.8


Threw in the last two as a .223/.22-250 analogy, NOT that you'd ever use a round nose, poor B.C. projectile at those velocities. Check out how many FPS a supersonic .22LR loses in the first 100-150 yards versu their subsonic partners...that's indicative of the delay time.

Notice the trend, notice that the section of the range where the bullet spends most of it's time trans-sonic is the worst affected (1,600fps, the 100Y starts coming back in, while the 200Y is worse)...

Apples and Orange Comparison then to compare the behaviours of a .223/.22-250 at mach 3, but plug them in and see also.
Hornady A-Max, B.C. 0.435
Code:


Velocity 100Y 200Y

3600 0.6 2.3

3200 0.7 2.6

.

.

.

2000 1.3 5.1

1600 1.7 6.6

1400 1.8 7.2

1200 1.8 6.7

1000 1.3 4.9


Same thing happens...but the higher B.C. will ALWAYS have less wind drift than the poorer.
And in the caseof the A-Max, it doesn't get the drift advantage back until 2,000FPS...mach 3...of course it conforms to sensibilities.


egg...face...

 

[ZeeOSix]

You said: "Firstly, because facts are as I've demonstrated (and every reputable ballistics calculator will tell you), in the range 1,000 to 2,000 fps that for two identical projectiles, the 1,000fps projectile will have less drift...period."

Using the Hornady calculator, the examples I ran showed the same identical bullet at 1000 fps had less wind drift than at 2000 fps until the 300 yard mark.

 

[Shannow]

Originally Posted By: ZeeOSix
You said: "Firstly, because facts are as I've demonstrated (and every reputable ballistics calculator will tell you), in the range 1,000 to 2,000 fps that for two identical projectiles, the 1,000fps projectile will have less drift...period."

In every example using the Hornady calculator, the wind drift is always less for the same exact bullet at 1000 fps vs. 2000 fps. The examples I ran showed the same bullet at 1000 fps had less wind drift than at 2000 fps.


"Range"...did you even read my post ?

You are adopting your usual techniques here.

did you do 1,000, 1,200, 1,400, 1,600, 1,800, 2,000...i.e. range.

the 1,000 and 2,000 are where the transonic phenomenon starts to settle down into the traditional sensible phenomenon...

Originally Posted By: Shannow
Pick a B.C. of 0.13 (not good, but rimfire typical), and 10MPH cross wind
Code:


Velocity 100Y 200Y

1000 4" 15"

1200 5.4 19

1400 6.0 21.8

1600 5.7 22.4

1800 5.1 21.6

2000 4.5 19.9

.

.

3200 2.3 10.4

3600 2.0 8.8


Well there goes your "every example", with a typical low velocity projectile at the 1,000 and 2,000fps....WOWO, look what happens in the middle...you can even TRY using numbers between those two velocities

Originally Posted By: Shannow
Hornady A-Max, B.C. 0.435
Code:


Velocity 100Y 200Y

3600 0.6 2.3

3200 0.7 2.6

.

.

.

2000 1.3 5.1

1600 1.7 6.6

1400 1.8 7.2

1200 1.8 6.7

1000 1.3 4.9




LOL, you ARE using your usual techniques...while I was responding,

Originally Posted By: ZeeOSix
You said: "Firstly, because facts are as I've demonstrated (and every reputable ballistics calculator will tell you), in the range 1,000 to 2,000 fps that for two identical projectiles, the 1,000fps projectile will have less drift...period."

In every example using the Hornady calculator, the wind drift is always less for the same exact bullet at 1000 fps vs. 2000 fps. The examples I ran showed the same bullet at 1000 fps had less wind drift than at 2000 fps.


became

Originally Posted By: ZeeOSix
You said: "Firstly, because facts are as I've demonstrated (and every reputable ballistics calculator will tell you), in the range 1,000 to 2,000 fps that for two identical projectiles, the 1,000fps projectile will have less drift...period."

Using the Hornady calculator, the examples I ran showed the same identical bullet at 1000 fps had less wind drift than at 2000 fps at every distance down range.


backpedalling without showing that you've edited it is the same old same old zee...now use exactly those axamples in the middle of the "range" that I suggested...

please, and post the results.

 

[Shannow]

BTW, I haven't shot ANYTHING with a 0.5BC, particularly at trans-sonic speeds...hmm...

edit, plugged it in, at 1,500fps, and it was 1.5" at 100 yards...well there ya go.

still am REALLY interested in why you chose the 0.5BC...

 

[ZeeOSix]

Settle down man, I'm just saying your statement isn't always true. Look at the wind drift results in the charts above. Out to 100 yards (zero sight in range) the bullet at 2000 fps had less wind drift than the one at 1000 fps. You made a statement specifically comparing 1000 fps to 2000 fps and claimed the 1000 fps bullet always has less wind drift. Not in the case I ran.

 

[ZeeOSix]

Originally Posted By: Shannow
BTW, I haven't shot ANYTHING with a 0.5BC, particularly at trans-sonic speeds...hmm...

edit, plugged it in, at 1,500fps, and it was 1.5" at 100 yards...well there ya go.

still am REALLY interested in why you chose the 0.5BC...


If what you're saying holds true, then it shouldn't matter what variables are used as long as all variables are identical except the muzzle velocity - that's why I chose those variables (most where default values).

And yes, It does shift at 1500 fps as you say. But I'm nit picking on your statement that identical bullets at 1000 fps will always have less wind drift (all other variables constant) than the same one at 2000 fps. Not quite that simple, as the example I showed says the 2000 fps bullet has less wind drift at 100 yards than in the 1000 fps case.

 

[Shannow]

Originally Posted By: ZeeOSix
You made a statement specifically comparing 1000 fps to 2000 fps and claimed the 1000 fps bullet always has less wind drift. Not in the case I ran.


RANGE...and my posts...including "RANGE". I STATED range, as the "range" in the middle is where all the funny stuff happens.

My examples INCLUDED what happens in the "RANGE"...

YOUR example (of a 0.5BC transonic projectile funnily enough) has more drift in the RANGE...only coming back to normal expectations at the end of it (thus the definition of a "range" in which it behaves contrary to intuition.

 

[ZeeOSix]

"... in the range 1,000 to 2,000 fps that for two identical projectiles, the 1,000fps projectile will have less drift...period." Not always period - I'm hair splitting now like you usually do.

Yes, I see that it goes wonky between 1000 fps and 2000 fps ... but the example I showed had the 2000 fps case having less drift at 100 yards than the 1000 fps case - those numbers are withing the RANGE of 1000 to 2000 fps. Run some others similar examples and you might see that the 1000 fps projectile doesn't always have less wind drift.

And yes, when really screaming (2500+ fps) then wind drift really cuts back a lot. It would be interesting to plot the same bullet over a wide muzzle velocity range and yards out to see how the family of curves look.

 

[Shannow]

Yes, I'm familiar with your hair splitting...standing neck deep in water next to a no swimming sign is fine, as you aren't completing stroke perfect Australian Crawl.

 

[ZeeOSix]

LoL ... actually, you're more of a hair splitter than I am. And big difference between neck deep and ankle deep ... exaggeration is even worse than hair splitting.

Merry Christmas!

 

[edhackett]

This has been an interesting thread. In looking up the BC of 22LR, I came across this paper:

Aerodynamic Characteristics of Caliber .22 Long Rifle Match Ammunition
http://www.dtic.mil/docs/citations/ADA229713

It was interesting in that they found that even a subsonic round fired a bit slower was even less wind sensitive. That makes sense as there would be less transonic signature as you moved toward a speed near, or just below the transonic range.
Quote:
The final part of the BRL wind study examined the effect of different muzzle velocities on the wind sensitivity of Eley Tenex ammunition. Muzzle velocities ranging from 1100 fps down to 800 fps were tried, with a 10 mph crosswind. The results showed that a muzzle velocity of approximately 950 fps gives minimum wind sensitivity for the Eley Tenex bullet, at both the 50 metre and 100 metre ranges. The wind sensitivity at a muzzle velocity of 950 fps would be approximately 20 percent less than that experienced at the standard velocity of 1090 fps.


Ed

 

[Shannow]

awesome find ed, thanks

 

[ZeeOSix]

Originally Posted By: ZeeOSix
It would be interesting to plot the same bullet over a wide muzzle velocity range and yards out to see how the family of curves look.

 

[Shannow]

Yep, that's it...did a step wise model for .22s back in the '90s that showed the same, but I only went to 2,000fps.

Clearly not time of flight, indicated in the shift in peak deflection with range.

 

[billt460]

Originally Posted By: Shannow
Originally Posted By: billt460
Then how can you possibly not know a .22 Magnum drifts less than a .22 L.R. at 100 yards?


Firstly, because facts are as I've demonstrated (and every reputable ballistics calculator will tell you), in the range 1,000 to 2,000 fps that for two identical projectiles, the 1,000fps projectile will have less drift...period...if you've got a better BC in the magnum, it's drift will improve...but put that same bullet at 1,000fps, and it will be better too.

Secondly, ad in line with the first point, 15 years in the rimfire club, and I never met a person whose scores didn't improve when I convinced them to drop high and hyper velocity .22s and go back to standards...you see, they were fixated on time of flight, not wat actually happens.

Thirdly, in that same period I NEVER saw a decent score shot with a Magnum. The proponents of the cartridge at the smallbore range tended to be loud (noisy rifles, noisy owners) poseurs.


So.... Yet again.....You've never actually shot both, (.22 L.R. / .22 Magnum), side by side in the same crosswind conditions. We're back to charts again. This time adding insults to .22 Magnum owners. (Which everyone knows are not as accurate as L.R.'s for target use).

 

[Shannow]

OK, so what statistical techniques have you used to determine the inherent inaccuracy of the round (your contribution), to your observed reduction in wind drift, in the face of established science ?

I meant to add to the "loud" point that those who bring magnums to rimfire shoots have a fundamental misunderstanding of physics and statistical techniques to shooting targets...

 

[billt460]

Originally Posted By: Shannow
OK, so what statistical techniques have you used to determine the inherent inaccuracy of the round (your contribution)?


No, it was actually yours. I'm simply agreeing with you.

Originally Posted By: Shannow
Thirdly, in that same period I NEVER saw a decent score shot with a Magnum.


The .22 Magnum is not as accurate of a cartridge as the .22 L.R. Especially when compared to purpose built .22 L.R. target rifles using expensive competition ammunition, which doesn't even exist for the .22 Magnum. And I have never argued that point. It's popularity comes from small game hunting at ranges beyond what a .22 L.R. is capable of. While it's capable of decent accuracy, it's never been known as a, "target cartridge". Which pretty well explains why you've never seen a decent score shot with one. (Although the late Tom Knapp was capable of some magnificent trick shooting with one.)

I'm not "into statistics" like you are. They're helpful sure, but they're not gospel. Especially in this case when you have someone who has discovered differently in actual conditions and comparisons. I'm not trying to argue with your with charts and graphs. I'm merely telling you, I have never seen a .22 L.R. drift less than an equal weight bullet in .22 Magnum under identical range conditions. And all I'm asking you is, have you EVER compared both cartridges side by side in actual cross wind conditions? And I've asked you this several times on this, and the other thread. You, for whatever reason, refuse to answer. This was no exception. You continually come back with charts, graphs, and "scientific data". I get it. You like and trust computer data. And in this case the data seems to support your argument. I've experienced differently in ACTUAL CONDITIONS. I'm not understanding why you haven't tried proving this out yourself? Especially with all the shooting you do.

 

[ZeeOSix]

Looking at ballistics, it looks like the .22 Mag would not drift as much as the .22 LR because the .22 Mag muzzle velocity is much higher and towards the right end of the wind drift curve compared to the .22 LR. And it would also depend on what exact brand/model of round was being fired. It's not so cut and dried.

.22 LR
http://www.ballisticsbytheinch.com/22.html

.22 Mag
http://www.ballisticsbytheinch.com/22mag.html

For example, if shooting at 100 yards from an 18" barrel, most of the .22 LR listed is in the 1100 to 1500 fps muzzle velocity range. The .22 Mag through the 18" barrel is in the 1800 to 2300 fps range.

So if you where shooting .22 LR with a muzzle velocity of 1500 fps the wind drift would be 3.8 inches, but if shooting the .22 Mag with 2300 fps the wind drift would be 2.3 inches.

Looking at the plot, the .22 LR velocity range is in the area where the wind drift would be the highest (peaks at 1400 fps), and the .22 Mag velocity range is shifted to the right where the wind drift starts coming down.

So based on this info, I'd say in general that .22 LR will have more wind drift than a .22 Mag in the same cross wind.