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Eric Cortina and Hornady

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.
Long range br shooters tune the same way. If it shoots it shoots.
 
I don’t begrudge people who are in to that kind of thing or are smarter than me, we need those people too. But if that level of math and statistics are required I’m screwed. It sounds like a total buzzkill. Looks like a great way to turn a passion into a migraine.
AGREE,.. Once, I've "Proved" my Rifle and Load, with at least, 3,.. 5 shot groups, AFTER that, it's JUST, ME,.. making, the Groups,.. Larger. ALL, my Rifles shoot,.. BETTER than,.. I can !
My son and I argued for 3 Days and IT gave me, a Headache,.. so,. I "Threw in, the Towel" !
Get enough Migraines, watching,.. the News !
 
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.
That's cute. Throw politics into a discussion where it doesn't need to be, blame the politician you don't like, but IGNORE $30 trillion in bailouts (to both domestic and foreign financial institutions) from the Federal Reserve during the administration before the one you didn't like. When you don't have a full grasp of a topic, it is best to leave it alone and try to keep it out of non-political topics. You're not helping.
 
I>
why would anyone believe the claim that SD = 0.3 x Groupsize as a statistical constant?
I didn't get the impression Bryan was claiming there to be a universal constant involved. My understanding of what he was saying was that of the 3 rifles (maybe more than one 375 cal, he didn't elaborate) he did large sample testing on, they saw a ~30% SD in those tests. Between 12:30-20:15 min is where he talks about it.

 
I>

I didn't get the impression Bryan was claiming there to be a universal constant involved. My understanding of what he was saying was that of the 3 rifles (maybe more than one 375 cal, he didn't elaborate) he did large sample testing on, they saw a ~30% SD in those tests. Between 12:30-20:15 min is where he talks about it.


I don't know how many videos there are at this point, but I think it was one with Horn where Cortina asked about the applicability to BR and the 30% "rule" was used as in every one I've watched and admittingly skip thru to only catch the high points. Clearly this is a take away for many readers which is why I accentuated it.
 
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.

THAT^^^^

I shoot silhouette. HP I'm only shooting out to 500 and as long as I stay in the teens with my numbers and my groups are sub-MOA, it's all on me.

To be fair... my loading has progressed and been measurable as opposed to luck BECAUSE of info gleaned from here, Mr. Cortina AND Mr. Glasscock. I've taken what works for me and not worried about what doesn't matter for me.

(what I've never understood it people who get mad about things or info that cost them nothing...)

:)
 
As the system's precision capability increases the distribution decreases.
52646517321_a8c88ea76c_c.jpg


The Yellow curve represents a tuned high quality system with a narrow distribution.

The Blue curve accurately represents a less precise system, perhaps typical Hornady factory ammo in a hunting rifle.

System Yellow and system Blue may both average 1/2 moa groups, but system Yellow will never spit out a 1.25" group like Blue does occassionally.
 
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As the precision capability increases (rifle & ammunition) the distribution decreases.
52646517321_a8c88ea76c_c.jpg


The Yellow curve represents a tuned high quality system with a narrow distribution.

The Blue curve accurately represents a less precise system, perhaps typical Hornady factory ammo in a hunting rifle.

System Yellow and system Blue may both average 1/2 moa groups, but system Yellow will never shoot a 1.25" group like Blue does occassionally.
This…

https://i.kym-cdn.com/photos/images/original/000/566/702/3f2.jpeg1674596598472.png
 
As the precision capability increases (rifle & ammunition) the distribution decreases.
52646517321_a8c88ea76c_c.jpg


The Yellow curve represents a tuned high quality system with a narrow distribution.

The Blue curve accurately represents a less precise system, perhaps typical Hornady factory ammo in a hunting rifle.

System Yellow and system Blue may both average 1/2 moa groups, but system Yellow will never shoot a 1.25" group like Blue does occassionally.
I believe this is the best way to describe Hornady's outlook on accuracy.
 
Fair enough. Though, just for the sake of arguments, 10 shot groups tend to be considered a lot 'closer' to the 'truth' of what the gun is capable of, long term, than 3 or 5.

And if someone wants to step in and make the argument that the hyper-tuned guns used in short or long BR, or even some of the better F-class guns, follow something other than the normal distribution curve, I'd be open to that. Most of us here have had or have seen guns that tend to average / agg way better than they 'should', according to raw statistics. Rather than argue about whether they do or don't, I'd be more interested in the subject of *why* they don't appear to follow the norm.
It has been my opinion for a long time that we are making a mistake assuming shot "dispersion" is "normally" distributed - I think that is an invalid assumption. So if that is truly the case (as you've alluded to) then statistics, as most of us understand them, have little value in this discussion.
 
It has been my opinion for a long time that we are making a mistake assuming shot "dispersion" is "normally" distributed - I think that is an invalid assumption. So if that is truly the case (as you've alluded to) then statistics, as most of us understand them, have little value in this discussion.
You, my friend have hit the perverbial nail on the head.
 
It has been my opinion for a long time that we are making a mistake assuming shot "dispersion" is "normally" distributed - I think that is an invalid assumption. So if that is truly the case (as you've alluded to) then statistics, as most of us understand them, have little value in this discussion.

That would be a good experiment to set up and test to see what kind of dispersion we're really seeing.
 
That would be a good experiment to set up and test to see what kind of dispersion we're really seeing.
Yes, it would be an interesting experiment, but I doubt it would give use much valuable information. I think we would see that the more shots included in the population, the more close to "normal" the distribution would become and that is truly the issue.

I think that was one of the points that the guy from Hornady was trying to make in the interview - that a large population (2,000 for example) of shots will likely give you a fairly "normal" distribution. However, we as shooter/competitors don't really care about the "large population" distribution, we care about groups of 25 shots (that are sequentially loaded). So it is likely that each 25 shot group will have a very different distribution than either the large population, the next or previous 25 shot group and they will very likely not be "normal".
 
Yes, it would be an interesting experiment, but I doubt it would give use much valuable information. I think we would see that the more shots included in the population, the more close to "normal" the distribution would become and that is truly the issue.

I think that was one of the points that the guy from Hornady was trying to make in the interview - that a large population (2,000 for example) of shots will likely give you a fairly "normal" distribution. However, we as shooter/competitors don't really care about the "large population" distribution, we care about groups of 25 shots (that are sequentially loaded). So it is likely that each 25 shot group will have a very different distribution than either the large population, the next or previous 25 shot group and they will very likely not be "normal".
This is a comprehensive discussion, full of the statistical theory.
As I mentioned earlier, the positions of the individual shots are the observations which are the proper inputs from which to develop the statistics. Group sizes are statistics, and are not observations, and are in no way normally distributed.
 

This is a comprehensive discussion, full of the statistical theory.
As I mentioned earlier, the positions of the individual shots are the observations which are the proper inputs from which to develop the statistics. Group sizes are statistics, and are not observations, and are in no way normally distributed.
I don't think I said anything about "group size", did I? I did reference "groups" of 25 shots. Also, I agree with you that "group size" itself can't be normally distributed, but certainly the mean radius of each of the shots ("observations") making up that group can be analyzed for their distribution.
 
I don't think I said anything about "group size", did I? I did reference "groups" of 25 shots. Also, I agree with you that "group size" itself can't be normally distributed, but certainly the mean radius of each of the shots ("observations") making up that group can be analyzed for their distribution.
Just trying to make it clear for the readers because the Horn discussion is regarding group size.
 
Erik is a personality, there is no question about that!

I'm not trying to be Erik. I would rather quit shooting than engage in the ambush interview tactics that Erik uses. Ever notice that I always wave him off?

Far too many people concentrate on the weird reloading stuff that top 10 shooter swear by. Honestly, we all do things that look suspiciously like superstition. The simpler I make my system, the easier it is for me to shoot the scores necessary to obtain those shiny neck weights.

For me, I have really cut back on the amount of YouTube content I'm making. Instead, I am focusing on my Patrons. They are the ones that make it possible to run tests, and make videos. You would be shocked at the expense doing such things entails. It just isn't worth it to put information out for free in many cases and deal with the endless trolls that pop up.

You have to remember what YouTube is at its core: An advertising platform. Have you noticed that everyone is trying to get you to buy stuff? Either stuff they make, or stuff they have a deal with the seller on? Even I'm selling something - my time answering questions, having Zoom meetings with individual Patrons, and the like.

I had thought about doing podcasts, but decided against that for a variety of reasons, not least of which is the fact that I can't bring myself to sit and watch anyone else's podcasts...

Back on subject:

Making videos and learning stuff for my team and patrons has netted me a lot of information that I would have not found otherwise. For example, I shot a very large sample for chronograph data while doing some large samples on tuning and group size. Oddly enough, there is a normal distribution of group sizes when you put over 100 rounds into the berm. If I take a standard deviation from those group sizes, I see that there is the likelihood of having an exceptionally large group and an exceptionally small one as well, over the life of the barrel.

On the other hand, I also wonder a bit about using group size at all for determining the precision of a rifle. Some other measurements show promise as better means of determining our likely outcomes from shooting very large samples (like an entire barrel worth).
I, for one, find your videos engaging and enlightening. Thanks for doing the work to post them!
 

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