Your Groups Are Too Small

[Formidilosus]

If the input in the WEZ for wind is the SD (standard deviation) on wind error, and you say you can call it within +/-4 mph 95% of the time. I think thats like saying 2*sd= 4mph. and would expect that "

gives a SD of 4mph/2=2 mph.
Because 2 SD captures 95% of occurrences? If the WEZ has specific documentation that says the SD input should be what you expect to see 95% of the time and its not standard deviation ignore me.

It is not SD. This can all be found in “Accuracy and Precision For Long Range Shooting” by Bryan Litz.


It’s 95% confidence at the stated MPH, then it follows a normal distribution.




To give an idea of “realistic” wind calling ability (and I can state that even this is being generous)-



If some one does not practice regularly (every couple of weeks) in broken, mountainous terrain, in areas and shots they have never seen before, they are at best “novice”, and broken terrains with wind are “difficult” conditions. If it is someone that is shooting in the mountains with wind only once or twice a year for practice- they aren’t even “novice”- a realistic expectation is that frequently enough they can, and will be off their wind call 10-12 mph.




A note Bryan makes about making wind calls in canyons and broken terrain-

 

[Formidilosus]

@stan_wa

I edited my last post with more information. FWIW.

 

[huntnful]

600 yards, 12” square, wind +/- 4mph (I.E., you can call it within 4 mph 95% of the time)

1.5 MOA= 58.6% 1st round hit probability-
View attachment 659848



1 MOA= 61.4% 1st round hit probability-
View attachment 659852



For a difference of less than 3%. You will not see this in the field. 5% takes a lot of shooting and logging (hundreds, to thousands of novel, 1st round of the day shooting in novel conditions). 10% is about where you can observe a difference with a day of shooting.



Let’s say you are shooting in novel mountain conditions, and winds weekly, and are a near world class wind caller.

600 yards, 12” square, wind +/- 2mph (I.E., you can call it within 2 mph 95% of the time)


1.5 MOA= 84.2% 1st round hit probability-
View attachment 659853


1 MOA= 89.4% first round hit probability-
View attachment 659854



A difference of 5.2%. There are very few people that are skilled enough, practiced enough, and shoot enough to see 5% difference in mountainous conditions with wind, on terrain they’ve never shot before.



Now let’s look at reality here. The way the program runs this is not an aggregate of x amount of 3 or 5 shot groups. It is based on a perfect zero, and 95% probability of group size- I.E., 30 shot extreme spread at 100 yards. To clarify- for “1 MOA”, it’s saying that you setup, shoot one round at 1” target at 100 yards, and you hit it- 30 times in a row on demand. How many people do that? But, let’s say you and your rifle system does do that on demand, you aren’t doing it on animals, in the field.
The best field shooters are about 1.5 MOA on demand with solid non competition rifles. Really skilled ones are about 2 MOA.

This info hurts my feelings, as far as realistic ability to hit things. And also makes me feel better that I don't need bughole groups in order to hit things haha. And honestly a 12" square is a pretty generous target. Definitely elk sized. A deer would maybe even be a 10" circle or so lol.

And this is only at 600 yards! A relatively "easy" shot, in a calm controlled environment.

 

[solarshooter]

600 yards, 12” square, wind +/- 4mph (I.E., you can call it within 4 mph 95% of the time)

1.5 MOA= 58.6% 1st round hit probability-
View attachment 659848



1 MOA= 61.4% 1st round hit probability-
View attachment 659852



For a difference of less than 3%. You will not see this in the field. 5% takes a lot of shooting and logging (hundreds, to thousands of novel, 1st round of the day shooting in novel conditions). 10% is about where you can observe a difference with a day of shooting.



Let’s say you are shooting in novel mountain conditions, and winds weekly, and are a near world class wind caller.

600 yards, 12” square, wind +/- 2mph (I.E., you can call it within 2 mph 95% of the time)


1.5 MOA= 84.2% 1st round hit probability-
View attachment 659853


1 MOA= 89.4% first round hit probability-
View attachment 659854



A difference of 5.2%. There are very few people that are skilled enough, practiced enough, and shoot enough to see 5% difference in mountainous conditions with wind, on terrain they’ve never shot before.



Now let’s look at reality here. The way the program runs this is not an aggregate of x amount of 3 or 5 shot groups. It is based on a perfect zero, and 95% probability of group size- I.E., 30 shot extreme spread at 100 yards. To clarify- for “1 MOA”, it’s saying that you setup, shoot one round at 1” target at 100 yards, and you hit it- 30 times in a row on demand. How many people do that? But, let’s say you and your rifle system does do that on demand, you aren’t doing it on animals, in the field.
The best field shooters are about 1.5 MOA on demand with solid non competition rifles. Really skilled ones are about 2 MOA.

This info hurts my feelings, as far as realistic ability to hit things. And also makes me feel better that I don't need bughole groups in order to hit things haha. And honestly a 12" square is a pretty generous target. Definitely elk sized. A deer would maybe even be a 10" circle or so lol.

And this is only at 600 yards! A relatively "easy" shot, in a calm controlled environment.

Yeah it's very enlightening. The cold bore challenge is interesting to look at, less than 50% overall success rate I think.

 

[Formidilosus]

This info hurts my feelings, as far as realistic ability to hit things. And also makes me feel better that I don't need bughole groups in order to hit things haha. And honestly a 12" square is a pretty generous target. Definitely elk sized. A deer would maybe even be a 10" circle or so lol.

And this is only at 600 yards! A relatively "easy" shot, in a calm controlled environment.

It should remove any notion of 600 yard field shooting being easy, or not that hard.

Understanding just this part of the reality of field shooting, should make clear why I write about 80% of what I do. Hit rates on demand drive my entire outlook.

 

[huntnful]

Yeah it's very enlightening. The cold bore challenge is interesting to look at, less than 50% overall success rate I think.

Yeah pretty cool info. I JUST shot my gun at 670 yards, in calm conditions, unbroken terrain. I would have went 4 for 4 on a 12” plate. But not a 10” circle. 3 for 4 on a 10” circle. Even though the group was only 4”. It was off to the upper right

 

[huntnful]

It should remove any notion of 600 yard field shooting being easy, or not that hard.

Understanding just this part of the reality of field shooting, should make clear why I write about 80% of what I do. Hit rates on demand drive my entire outlook.

Yes sir. Field shooting is certainly more difficult than planned daily shooting out at the range.

 

[huntnful]

It should remove any notion of 600 yard field shooting being easy, or not that hard.

Understanding just this part of the reality of field shooting, should make clear why I write about 80% of what I do. Hit rates on demand drive my entire outlook.

So when you lay down at 800 yards for example, to shoot an elk, you just accept the fact that your first round only has say, a 60% chance (just a guess, I don’t have WEZ or your personal data) of landing within 6” (12” circle) of your intended placement? Knowing full well that a follow up is going to be on the way within seconds after you see the first impact?

Not talking in a condescending tone either. Because that’s what I do. I just never knew the legit hit rate data. I Do my absolute best for a perfect first shot, and then send another one as soon as I can see to make a correction if need be

 

[Formidilosus]

So when you lay down at 800 yards for example, to shoot an elk, you just accept the fact that your first round only has say, a 60% chance (just a guess, I don’t have WEZ or your personal data) of landing within 6” (12” circle) of your intended placement?

Breaking this into pieces.

1st- as an overall concept- I take shots where I have an extremely high probability (90-95% plus) of standing over that animal at the end of the event. Everything goes into that probability- target, range, conditions, wind, shooting system, position, terrain, snow versus not, etc., etc.
There are times that I will kill an animal where my first round hit probability may be 70% because the situation allows an almost guaranteed recovery; and there are times where I won’t take a shot when my first round hit probability is close to 90% simply because if I miss the odds of recovering the animal are poor.

Second, the vitals of an elk are far larger than 12”. I use 18” to give some margin as they are irregular in shape, but 24”’is realistic. At 800 yards in most conditions I am around 80% or higher for first round hit probability.


Third, in general I wouldn’t suggest taking shots where someone is not in the 90-95% probability of first round vital hit for that exact shot- which means far shorter than what people believe, and even shorter still because few are actually practicing in the environments they hunt in.
From what I have observed when someone really believes they are “100% confident” on a shot- they are around 70% or less. When they believe they are 90% probability of a hit- they are below 50%.

People do not shoot enough to have any real idea what their hit percentage is.

Knowing full well that a follow up is going to be on the way within seconds after you see the first impact?
Not talking in a condescending tone either. Because that’s what I do. I just never knew the legit hit rate data. I Do my absolute best for a perfect first shot, and then send another one as soon as I can see to make a correction if need be

Always immediate follow up shots regardless of range, cartridge, or placement- as soon as the bullet impacts, rack, and press another shot immediately. Shoot them to the ground.

 

[huntnful]

Breaking this into pieces.

1st- as an overall concept- I take shots where I have an extremely high probability (90-95% plus) of standing over that animal at the end of the event. Everything goes into that probability- target, range, conditions, wind, shooting system, position, terrain, snow versus not, etc., etc.
There are times that I will kill an animal where my first round hit probability may be 70% because the situation allows an almost guaranteed recovery; and there are times where I won’t take a shot when my first round hit probability is close to 90% simply because if I miss the odds of recovering the animal are poor.

Second, the vitals of an elk are far larger than 12”. I use 18” to give some margin as they are irregular in shape, but 24”’is realistic. At 800 yards in most conditions I am around 80% or higher for first round hit probability.


Third, in general I wouldn’t suggest taking shots where someone is not in the 90-95% probability of first round vital hit for that exact shot- which means far shorter than what people believe, and even shorter still because few are actually practicing in the environments they hunt in.
From what I have observed when someone really believes they are “100% confident” on a shot- they are around 70% or less. When they believe they are 90% probability of a hit- they are below 50%.

People do not shoot enough to have any real idea what their hit percentage is.






Always immediate follow up shots regardless of range, cartridge, or placement- as soon as the bullet impacts, rack, and press another shot immediately. Shoot them to the ground.

Awesome. I really appreciate the detailed response. And that whole break down makes perfect sense honestly. Thank you

 

[solarshooter]

Breaking this into pieces.

1st- as an overall concept- I take shots where I have an extremely high probability (90-95% plus) of standing over that animal at the end of the event. Everything goes into that probability- target, range, conditions, wind, shooting system, position, terrain, snow versus not, etc., etc.
There are times that I will kill an animal where my first round hit probability may be 70% because the situation allows an almost guaranteed recovery; and there are times where I won’t take a shot when my first round hit probability is close to 90% simply because if I miss the odds of recovering the animal are poor.

Second, the vitals of an elk are far larger than 12”. I use 18” to give some margin as they are irregular in shape, but 24”’is realistic. At 800 yards in most conditions I am around 80% or higher for first round hit probability.


Third, in general I wouldn’t suggest taking shots where someone is not in the 90-95% probability of first round vital hit for that exact shot- which means far shorter than what people believe, and even shorter still because few are actually practicing in the environments they hunt in.
From what I have observed when someone really believes they are “100% confident” on a shot- they are around 70% or less. When they believe they are 90% probability of a hit- they are below 50%.

People do not shoot enough to have any real idea what their hit percentage is.






Always immediate follow up shots regardless of range, cartridge, or placement- as soon as the bullet impacts, rack, and press another shot immediately. Shoot them to the ground.

So what would be some realistic ranges that correspond to >90% hit probability for regular shooters with regular and magnum cartridges? I'm guessing 4-500 yards? It depends on the wind so maybe there is a rule of thumb we could work out using wez where as yardage increases windage decreases to maintain a constant hit percentage threshold?

And while we're on the subject, I know you're a big proponent of lighter recoiling cartridges like .223 because of recoil management and spotting impacts. But given these might have twice the windage and thus twice the wind error of say a 7RM, it would seem like it's worth the error due to recoil to reduce the error due to wind.

 

[willfrye027]

Not disagreeing with Form, but most of my shot opportunities are at first light when there is minimal, like 1-3mph wind. That FEELS like a lot easier of a wind call to make.

I know I do not shoot near enough in the mountains.. but when I do it’s a dramatic first round hit difference between calm/light wind and medium or heavy wind. There is a huge difference between me calling 2-3mph wind which I feel fairly confident in, and trying to call 6-8mph wind or guessing what effect the thermals and swirling winds might have.

 

[Formidilosus]

So what would be some realistic ranges that correspond to >90% hit probability for regular shooters with regular and magnum cartridges? I'm guessing 4-500 yards?

Nowhere close to 400 yards. Sub 200 yards, and generally less than 100 yards.
A data set that is available is the Colorado cow elk hunt in the Park and San Luis Valley. Volunteers put in and are selected and then must attend a qualification where they have to hit a 14” target 3 times in a row at 200 yards from any position other than prone- supported with bipod or tripod is fine; and 3 times in a row at 300 yards from prone in order to hunt.
All of the participants know the requirement, and are even allowed to practice on the range. They generally have 30-35 hunters show up per session, and the average that hit a 14” plate at 200 and 300 yards three times each, is between 0 and 3 people out of 30+.

This performance, or lack thereof is not abnormal- that is actually better than average, because everyone knows what they have to do to qualify. It’s interesting to read multiple threads on different boards about this hunt and qual, including from people that have participated- and how many actually passed after arguing how it was so easy.

It depends on the wind so maybe there is a rule of thumb we could work out using wez where as yardage increases windage decreases to maintain a constant hit percentage threshold?

If you aren’t shooting in the wind, in broken terrain constantly- don’t shoot in the wind past 150-200 yards.

And while we're on the subject, I know you're a big proponent of lighter recoiling cartridges like .223 because of recoil management and spotting impacts. But given these might have twice the windage and thus twice the wind error of say a 7RM, it would seem like it's worth the error due to recoil to reduce the error due to wind.

(Bolded)

No. The highest hit rates regardless of shooters skill, age, or sex inside of 500 yards are from properly setup, fast twist 223’s shooting good 70+ grain bullets.

We miss do to the largest source of error.

1). We suck

2). Loss of zero

3). No zero

4). Incorrect zero

5). Wind

In about that order.

 

[Antares]

So what would be some realistic ranges that correspond to >90% hit probability for regular shooters with regular and magnum cartridges? I'm guessing 4-500 yards?

Greater than 90% for “regular shooters”?

I know many, many people who have hunted their whole lives that would absolutely struggle to go 10 for 10 on a 10” plate at 200 yards.

 

[Formidilosus]

Not disagreeing with Form, but most of my shot opportunities are at first light when there is minimal, like 1-3mph wind. That FEELS like a lot easier of a wind call to make.

It’s definitely easier when it is a “no wind” situation. And it depends on where you are- ID seems to have less wind than MT or WY. CO seems to be in the middle. But…. The vast majority don’t have rifles or scopes that hold zero, almost all flinch or have anticipation, and most have no legitimate data.

I don’t know you, so this isn’t directed at you, however let’s look at the Cold Bore Challange. I have written and discussed the realities of hit rates in the field for close to a decade on here. Lots/most argued that I was FOS.
Then the CBC happened last year, and look how many people that SWORE 600 yards was easy missed both shots at sub 600 yards- actually look how many missed at sub 450 yards. Interestingly quite a few were ones that argued with me about it. Hit rates when actually measured for “do it right now” are way lower than people believe or claim.


How people believe they will successful at 600, 700, 800 yard or farther shots on animals when they practice less per year for that, than their 4 year old practices T-Ball is baffling.

 

[chamois]

600 yards, 12” square, wind +/- 4mph (I.E., you can call it within 4 mph 95% of the time)

1.5 MOA= 58.6% 1st round hit probability-
View attachment 659848



1 MOA= 61.4% 1st round hit probability-
View attachment 659852



For a difference of less than 3%. You will not see this in the field. 5% takes a lot of shooting and logging (hundreds, to thousands of novel, 1st round of the day shooting in novel conditions). 10% is about where you can observe a difference with a day of shooting.



Let’s say you are shooting in novel mountain conditions, and winds weekly, and are a near world class wind caller.

600 yards, 12” square, wind +/- 2mph (I.E., you can call it within 2 mph 95% of the time)


1.5 MOA= 84.2% 1st round hit probability-
View attachment 659853


1 MOA= 89.4% first round hit probability-
View attachment 659854



A difference of 5.2%. There are very few people that are skilled enough, practiced enough, and shoot enough to see 5% difference in mountainous conditions with wind, on terrain they’ve never shot before.



Now let’s look at reality here. The way the program runs this is not an aggregate of x amount of 3 or 5 shot groups. It is based on a perfect zero, and 95% probability of group size- I.E., 30 shot extreme spread at 100 yards. To clarify- for “1 MOA”, it’s saying that you setup, shoot one round at 1” target at 100 yards, and you hit it- 30 times in a row on demand. How many people do that? But, let’s say you and your rifle system does do that on demand, you aren’t doing it on animals, in the field.
The best field shooters are about 1.5 MOA on demand with solid non competition rifles. Really skilled ones are about 2 MOA.

This is oooh so enlightening and explains so many unexplainable situations (read misses) in the field...
The conclusions are quite clear: do not waste time and effort and components trying to squeeze the last 0.5 moa precision from your gun, practice shooting in field conditions, have your gun properly sighted in so she shoots where you are aiming, and get closer.
I was culling does two days ago with a friend and had him miss one at 456 meters. It left him scratching his head because he insisted that the picture looked perfect when the shot went off. I´ll try to make him read Formid's post though I know sometimes it is not possible to take a donkey to the water regardless how thirsty it is. We see it here every day.

 

[Macht]

All good. Thanks for linking this paper, I am about halfway through. I think so far everything I've said here is consistent with his analysis and findings.

Barrel deflections due to modal excitation from the shot are real and the main driver of rifle precision. Now, is "tuning" against these deflections possible? I think the consensus so far is yes by changing components, maybe/maybe not by changing only powder charge.

At the risk of sounding overly blunt, the methods and approach in that thesis are very simplistic, and at least somewhat wrong.

Given your profession, you have some tools at your disposal to prove that to yourself. Using your FE program of choice I'd suggest modeling a simple barrel in 3D, including a breech face but omitting the rifling (pain in the neck to mesh). Add some additional mass to the model attached to the breech face. This could be a point mass or an additional geometry with high density material properties, just make sure the CG lies on the barrel centerline. Load your chamber and breech face with something approximating a pressure curve (you can do a moving pressure front in the barrel if you feel like adding some work). Then repeat the above with the additional mass shifted off the centerline of the barrel.

You'll find that the off-axis loading will produce movement far greater than any vibration produced by the impulse load in the first model.

 

[HighUintas]

@Formidilosus , is there a method you recommend shooters use to figure out what their hit probability is for different distances and wind conditions that is more accurate than just keeping a rough log of their hit rate on different days of practice?

 

[stan_wa]

It is not SD. This can all be found in “Accuracy and Precision For Long Range Shooting” by Bryan Litz.

I think it’s possible your doubling the effect of the wind in the Wez calculator compared to what you’re saying based off the information you’ve provided. Let me explain why I say this.

For the inputs of 2 mph of wind deflection I checked and I get about 3.3 inches @ 600 yards. This tells me that the uncertainty column is the uncertainty due to that input.
It the inputs are extreme spread the horizontal displacement in one direction should be the the sum off the Input
- all horizontal uncertainty’s + 1/2 rifle precision * range
expected distribution, assuming the inputs are extreme spread-
3.5+ 1.5/2x6 = 8”

If the inputs are standard deviation as labeled, we would expect the total dispersion to be
2x standard deviation + 1/2 rifle precision * range. For 95 % of shots.

2x 3.5 + 1.5 *1/2 * 6 = 11.5

This linked picture looks much closer to 11 1/2 inch distance from Center rather than 8”.


All that said, if you think you can call the wind +/- 4 I think the Wez input should be two. If you think you can call the wind +/-10. I think the Wes input should be 5. because the input is standard deviation, which is half of the extreme spread.

 

[Formidilosus]

I think it’s possible your doubling the effect of the wind in the Wez calculator compared to what you’re saying based off the information you’ve provided. Let me explain why I say this.

For the inputs of 2 mph of wind deflection I checked and I get about 3.3 inches @ 600 yards. This tells me that the uncertainty column is the uncertainty due to that input.
It the inputs are extreme spread the horizontal displacement in one direction should be the the sum off the Input
- all horizontal uncertainty’s + 1/2 rifle precision * range
expected distribution, assuming the inputs are extreme spread-
3.5+ 1.5/2x6 = 8”

If the inputs are standard deviation as labeled, we would expect the total dispersion to be
2x standard deviation + 1/2 rifle precision * range. For 95 % of shots.

2x 3.5 + 1.5 *1/2 * 6 = 11.5

This linked picture looks much closer to 11 1/2 inch distance from Center rather than 8”.


All that said, if you think you can call the wind +/- 4 I think the Wez input should be two. If you think you can call the wind +/-10. I think the Wes input should be 5. because the input is standard deviation, which is half of the extreme spread.

Post 401 has pictures from the book with an example, and the note of how it is being modeled. Here it is again-




Here is a link to read the overview-

https://appliedballisticsllc.com/wp-content/uploads/2021/06/ABDOC115_ProbabalisticWEZ-2021-Copyright.pdf

I am not a mathematician, statistician, etc., regardless of how it is figured, it is used as I have done so here, and the the average level/ability of people and the hit rates that results are consistent in live fire.