Eric Cortina and Hornady

[memilanuk]

Pretty sure when you say something like "...generate 2 or 3 times the expected chamber pressure" you just kicked any credibility you might have had right in the 'nads. The reference is to +/- 2 or 3 times the standard deviation, not the mean itself.

 

[davidjoe]

I gleaned the that Hornady predicted some groups, two and three times larger, and maybe more, than the size of the mean group.

 

[memilanuk]

Nope. Listen more closely next time. They were discussing basic statistical probability, where (assuming things follow a 'normal' or Gaussian distribution curve) ~68% of the values fall within +/- 1 SD of the mean, ~95% fall within +/- 2 SD, and ~99.7% fall within +/- 3 SD. They were *trying* to communicate basic stats to the average shooter in terms they (the shooter) could relate with. Way too many people just jumped in with pre-conceived notions and completely blew past the foundational concepts.

Then you have other basic statistical concepts, like the central limit theorem, and the standard error of the mean (SEM).

 

[DLT]

While I use some Hornaday bullets with some success for varmint hunting / predator hunting, I don't know any serious match shooters that uses them.

The biggest advantage I see with them is that they are available whereas Sierra and Nosler, my two favorites are as scarce as a conservative in California.

Amen

 

[Bill Norris]

memilanuk said​

Way too many people just jumped in with pre-conceived notions and completely blew past the foundational concepts.

And way too many shooters & hand loaders (me included) don't understand all the big terms nor what the they mean as well. Simply above our pay grade. LOL.

 

[davidjoe]

Nope. Listen more closely next time. They were discussing basic statistical probability, where (assuming things follow a 'normal' or Gaussian distribution curve) ~68% of the values fall within +/- 1 SD of the mean, ~95% fall within +/- 2 SD, and ~99.7% fall within +/- 3 SD. They were *trying* to communicate basic stats to the average shooter in terms they (the shooter) could relate with. Way too many people just jumped in with pre-conceived notions and completely blew past the foundational concepts.

Then you have other basic statistical concepts, like the central limit theorem, and the standard error of the mean (SEM).

You’re on. I will. There’s three podcasts on the subject, and I’ll find the references that gave me this impression, and follow up.

 

[memilanuk]

​

And way too many shooters & hand loaders (me included) don't understand all the big terms nor what the they mean as well. Simply above our pay grade. LOL.

At this point, in 2023, those core concepts have been explained, using very small words many, many times over the last decade or two, specifically aimed at shooters just like you. If you haven't picked up on it by now, that's just willful on your part. And yet you persist in jumping in feet first and attempting to 'debate' the terms that you admit you don't understand.

Awesome.

 

[memilanuk]

You’re on. I will. There’s three podcasts on the subject, and I’ll find the references that gave me this impression, and follow up.

I'm sure if you go back through every single second of all three or more podcasts you can find a sound bite that if twisted out of context, could imply almost anything. Personally, I wouldn't waste three hours of your life re-listening to the podcasts simply to try and find where they may or may not have mis-spoke. Instead, spend those three hours actually brushing up on basic statistics. *FAR* better use of that time.

 

[Bill Norris]

At this point, in 2023, those core concepts have been explained, using very small words many, many times over the last decade or two, specifically aimed at shooters just like you. If you haven't picked up on it by now, that's just willful on your part. And yet you persist in jumping in feet first and attempting to 'debate' the terms that you admit you don't understand.

Awesome.

Right, I may NOT understand some of the terminology nor what it means and no I am not arguing that part at all. BUT, what I am arguing is what I see on my targets and what has worked for me in the past to develop my loads. And I still say that if I extended my 10 shot groups out to 10 groups I do not think I will shoot a group that measures 1/2 MOA. And nothing Hornady or anybody else tells me will convince me I'm wrong. To bring the big word "statistically" in I can say that rifle has not shot a 1/2 MOA group yet @ 100 yds.

 

[RickyK]

Man, Ya'll make my head hurt with all these big words and terminology .
All I do is step 30 yards behind my house and work my F Class loads up at 300 yards !

 

[memilanuk]

Right, I may NOT understand some of the terminology nor what it means and no I am not arguing that part at all. BUT, what I am arguing is what I see on my targets and what has worked for me in the past to develop my loads. And I still say that if I extended my 10 shot groups out to 10 groups I do not think I will shoot a group that measures 1/2 MOA. And nothing Hornady or anybody else tells me will convince me I'm wrong.

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.

 

[Keith Glasscock]

What do you mean by saying Erik uses ambush tactics? And when do you wave him off? I’m a subscriber to both you and Erik’s patreon/forum and I value you both equally. Just saying that because I’m not biased.

I've been criticized for not speaking to Erik when he shoves a camera in my face at a match without asking first. I always excuse myself from the impending "interview".

 

[Bill Norris]

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 *why* of why they don't appear to follow the norm.

I agree with you 100 % on that.

 

[Bill Clifton]

No, it's not the same. Wyoming if fortunate that it has no large urban areas filled with spineless sheep. If you travel in California's small towns and rural areas, there are lots of good folks who despise what happens in Sacramento. Nevada is an excellent example of a very conservative state that is dominated by Clark County, Las Vegas. This is true in more than a few states.

Unfortunately it's spreading to more states all the time.

 

[K22]

memilanuk said​

Way too many people just jumped in with pre-conceived notions and completely blew past the foundational concepts.

And way too many shooters & hand loaders (me included) don't understand all the big terms nor what the they mean as well. Simply above our pay grade. LOL.

Yea I'm with you, but I'll bet you shoot just fine and your reloads work just fine.

PS: It ain't rocket science.

 

[Bill Norris]

Yea I'm with you, but I'll bet you shoot just fine and your reloads work just fine.

PS: It ain't rocket science.

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.

 

[Keith Glasscock]

Right, I may NOT understand some of the terminology nor what it means and no I am not arguing that part at all. BUT, what I am arguing is what I see on my targets and what has worked for me in the past to develop my loads. And I still say that if I extended my 10 shot groups out to 10 groups I do not think I will shoot a group that measures 1/2 MOA. And nothing Hornady or anybody else tells me will convince me I'm wrong. To bring the big word "statistically" in I can say that rifle has not shot a 1/2 MOA group yet @ 100 yds.

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

So what does that mean? (pun intended)
Let's take IQ scores as an example (because this is a commonly used subject in statistics courses that I remember well):
The mean is 100
The Standard Deviation is 15

Therefore, we would expect 68% of the population to have an IQ between 85 and 115, 95% between 70 and 130, and 99.7% between 55 and 145.

A little math tells us to expect:
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.

If I am understanding what Litz said, he expects the SD to be 30% of the group size. In other words, out of 1000 groups, one would expect to have 1 that is average (mean) group size + 3 SD, or if Litz is right about the SD, for a .250 agg rifle, one in 1000 groups can be expected to be .465" or greater.

So, the idea of shooting 10, 10 shot groups is going down the right path, but that is only equivalent to shooting 20, 5 shot groups. In other words, you would need to shoot a lot more groups than that to disprove the statistics...

 

[Bill Norris]

Actually I am NOT concerned with disproving the statistics or anything else. I can only "Believe MY Target" and truthfully going back and looking at my data log I can see where the rifle has gone way past my expectations with grouping whether it is 3, 5, or 10 shot groups without seeing anything close to 1/2 MOA. So I will not entertain wasting components and my time to disprove something I don't already believe in.

 

[J.d. Popkes]

 

[Bill Norris]

View attachment 1403147

Yea, just simply back ground noise that don't mean a thing when it's just the shooter and the target getting together for a good session.