Eric Cortina and Hornady

[rijndael]

People forget that the problems with the economy/inflation
starts with the previous administration.

Everyone was too distracted by their shiny COVID stimulus payment, 1 and 2, to be worry about what comes next. The sad part is, no one in government learned that widespread shutdowns are a horrible idea.

 

[Dgd6mm]

Swallow coffee before clicking.
Utter nonsense.

Is that how f class shooters think and benchrester's don't?

 

[Bill Norris]

Hard to believe they all believe the b s.

 

[Darwin]

Is that how f class shooters think and benchrester's don't?

It’s just a utoob attention thing.

 

[K22]

Thanks for the word of confidence. I don't compete except with myself because I don't like traveling. But I do hand load and shoot quite a bit. According to my data log I shot a little over 5000 rounds last year with 22 LR, 6mm, 6.5, and .308 calibers. And as I mentioned in the other post I will not argue the big words and terms that purely mean nothing to me but what I see on my targets and what I did to be able to see those targets simply works for me. After all, the name of Erik's podcast is "Believe the Target" right.

You are already ahead of the game.

 

[davidjoe]

Let me step into the statistical debate here:

Standard deviation on a normally distributed bell-curve will produce approximately the following:
~68% of the population within plus or minus 1 standard deviation of the mean (average) value.
~95% of the population within plus or minus 2 standard deviations of the mean
~99.7% of the population within plus or minus 3 standard deviations of the mean

34% between 100 and 115
13.5% between 116 and 130
2.35% between 131 and 145
0.15% 146+
The other 50% between 0 (actually 10, different discussion - 6 sigma) and 99

So how does that work out for groups?
Each group is just one sample (score). In order to have a reasonable chance of seeing a group that is the mean size plus 3 times the standard deviation is 100 groups, and that is no guarantee that you will find one. Random chance plays a role in this too. It might take 200, 400, or 1000 to find that really big group.

Hello Keith, let me recast your IQ distribution with a different twist though, … if you had the same person, sit down and take the IQ test, with breaks of course, say over weeks, how many times would that person need to take it, in order to have a reliable indication of their true IQ?

I would posit that one test is all we actually administer, that two should be extremely close to each other, and that if you kept going, and a person’s scores encroached on everything from genius and extremely gifted, all the way down to clinical retardation, even rarely, then either the IQ test is invalid, or the person is mentally unreliable. We can rule out this kind of “unreliability” in objects like an inanimate gun, in a vice.

Similarly, it should not be possible for a person with a 10 IQ to score 140. In fact, the only way they could, would be if you let them take thousands of tests filling in bubbles - and then picked the single best result, ignoring the others, in which case, testing them only one time would actually be more reliable. A bell curve predicts untenable, illogical results will occur validly, if infrequently, even when there is no possible way they could.

The IQ test not only need not be administered a huge number of times, it also need not be unduly long. (They do not stretch into day over days, like the bar exam did.). They have determined that one test over something like one or two hours is reliable. Analogizing that to shooting, it would be like a shot string we would typically shoot, the first few establish what the ammo does, and the remainders vet a hot barrel changing poi.

 

[bobinpa]

Yes !! People forget that the problems with the economy/inflation
starts with the previous administration. Did'nt help that Trump
increased the debt by nearly 7 Trillion. Biden's problem is not being
capable of fixing it. and in most cases throwing more money at the
problem making it worse. And the snowball continues to roll no matter
who is in office.....

I apologize for being so far off on this thread.....I need to look at that
previous posted video of Lytz and Cortina.

I couldn't possibly disagree with you any more than I already do!!! I'd love to hear why it is better for a union like the UMWA to support a president like Biden who hates coal... And I'd love to hear you try to explain how Trump's economy with the lowest unemployment rate in 50 years and low interest rates, etc caused the mess we are in but I certainly don't want to derail this thread any further...

Edit to add: I apologize to the OP for getting off topic.

 

[rijndael]

I couldn't possibly disagree with you any more than I already do!!! I'd love to hear why it is better for a union like the UMWA to support a president like Biden who hates coal...

Did we read the same post by Fuji? That's not what I got from his post.

But, regarding Trump's economy, the idea of throwing thousands and thousands of dollars in tax credits to Americans, under the blanket of "covid relief", started with Trump. That contributed to the inflationary damage we're going through now. Biden continued it.

 

[TC260]

Edit to add: I apologize to the OP for getting off topic.

It happens, no worries...but could we kindly ask to take the political discussion over to a different thread?

 

[STS]

Swallow coffee before clicking.
Utter nonsense.

Those two guys might be starting a new shooting discipline. The "Chronograph Match." There's no need to drive to a range. Just take a screen shot of your chronograph numbers and send it in. The lowest SD wins.

 

[Dusty Stevens]

Looks like Erik created his own forum.

Cortina Precision Forum

Cortina Precision Discussion Board

www.shootsmallgroups.com

Jeff

And lives rent free in the minds of many

 

[rogina]

Is that how f class shooters think and benchrester's don't?

WHAT???

 

[JFrank]

View attachment 1403147

I do not follow the math ‘ but I do use three shot testing , and when I add more population I get aggs like this

 

[Dgd6mm]

He thinks....but wait....the other guy is a better wind reader and a little more patient.
Coulda, woulda, if.....
Oh, and let's say it's someone else and not Litz that thinks this way.
I've read many times that the best es and sd doesn't win in br.

 

[CharlieNC]

WHAT IS GROUP SIZE?

When you shoot a group with 2,3,5,10,20 or whatever number, the INDIVIDUAL SHOTS ARE THE OBSERVATIONS. You can measure every individual shot and calculate numerous statistical parameters, or you can just measure the min vs the max such that the group size is the statistical range of the observations. The RANGE (GROUP) IS A STATISTIC, not an observation. If you do a little research you will find the range is NOT normally distributed. There is no such thing as calculating the standard deviation of the range (equivalent to taking the SD of the SD), and various statistical tests for the range are are conducted using the average range. These tests can be applied to test whether the current observation is different than history, of if the range for item A is different than item B where the history does not matter. Even overlooking such gross misuse, why would anyone believe the claim that SD = 0.3 x Groupsize as a statistical constant?

Shooting statistics are quite complex, and in the 1960's the military et al began to publish numerous articles suggesting the use of other parameters based on the distance of each shot from the center point (mean radius, SD of the radius, SDvertical, SDhorz, etc) to characterize hits from weaponry (including missles). You would be better served considering these analyses which are based on actual statistical methodology vs voodu.

 

[Louisiana Shooter]

At least be as smart as a goose.

Eat the corn and not the rocks.

As for the political comments - obviously no one is tired enough of any of this BS to DO anything about it yet. SOOO it will continue to get worse. Get used to it or do something about it.

 

[Kracken McGraw]

And lives rent free in the minds of many

We will pass the plate as we sing hymn 6.5-284.

 

[Keith Glasscock]

Non-intuitive, but Bryan is right for F-class in regards to the impact of velocity standard deviation. Closed loop systems work that way.

I'm not sure about 4 SD vs 7 SD, But 4 SD vs 8 SD is something I'd bet on, all else being equal (ballistics, wind calls, etc.).

 

[Wolfdog91]

....am I the only one lost as hell rn ?

 

[jackieschmidt]

Non-intuitive, but Bryan is right for F-class in regards to the impact of velocity standard deviation. Closed loop systems work that way.

I'm not sure about 4 SD vs 7 SD, But 4 SD vs 8 SD is something I'd bet on, all else being equal (ballistics, wind calls, etc.).

Even though I am not a Long Range Shooter, I can se the point that Bryan is making.

If you go to the line at 600/1000 yards with a tune that is locked into a specific vertical dispersion due to extreme velocity spreads, there isn’t a darn thing you can do about it.

That is the single biggest difference in the way we Short Range Benchrest Shooters tune and the way Long Range Shooters tune. In short range, the only thing that matters is the group size, or agging capability. I have shot sub .200 10 shot groups with my Rail Gun over my Ohler 35 that had a velocity spread as much as 30+ fps. That would be atrocious in a 600/1000 yard Discipline.

But you can bet I am going to the line with that tune. It just doesn’t matter that much at 100/200 yards.

So many times we got caught up in what counts in our own particular Discipline that we forget that other Disciplines have different parameters that allow the Combination to be competitive.