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Scatter Node Test?

I'm assuming when going to a match, everyone uses the good node from their load development. And from that, you gather data.

Has anyone ever done negative testing where they take their scatter node and see how it groups for say a 20 shot string to compare it to the good node?

[When I get time I'm gonna try this]
 
What improvement in your groups and shooting can possibly learned from trying to make a bigger group? Load them the best way you know how and wait for a windy day and find out how bad the wind moves them then you can shoot some bad groups and learn something at the same time.
 
I'm assuming when going to a match, everyone uses the good node from their load development. And from that, you gather data.

Has anyone ever done negative testing where they take their scatter node and see how it groups for say a 20 shot string to compare it to the good node?

[When I get time I'm gonna try this]
I think this is observed very often at 1K IBS matches..
Most will run their load at that last tenth grain of powder before vertical.
The results are 1.5-3.5” groups during the first relay and if load comes out of tune,
7-10” groups on the next one..
Is this what your testing for? Maybe I’m misunderstanding your question?
 
Pretty soon reading this forum will be like reading a newspaper. Worthless. I remember when it was about real accuracy with questions and thoughts died into actual testing ans results from actual competition. Sad.
I know Dan Newberry, who coined OCW and scatter node terminology, likes to observe the scatter node as evidence of proper selection. But not with many shots, just the typical OCW test.


Jeff

My point is to validate and use negative testing to verify that the correct node was selected much like Charlie states above (just with more shots). If the scatter node shoots very poorly in comparison to the selected node at distance, then that further verifies the selected charge. Why just do positive testing when you can further verify with negative testing if it truly only costs ~25 shots?

But what if the scatter node barely shoots worse than the selected node? Maybe that means I need to reassess the selected charge.

For example, in the attached group. I'd like to see what 52 does at distance vs 50.9 or 52.7
 

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Practice doesn't make perfect, perfect practice makes perfect. Shooting your worst group doesn't tell you a group is best. Shooting 4 or 5 best groups tells you whats best. Please explain to me shooting with the intention of making a back group tells you anything?
 
Practice doesn't make perfect, perfect practice makes perfect. Shooting your worst group doesn't tell you a group is best. Shooting 4 or 5 best groups tells you whats best. Please explain to me shooting with the intention of making a back group tells you anything?
I'll pose the following:

Using the above charge weights, what would it tell you if 52 and 50.9 shot roughly the same at distance over 20 or so shots?

AND

In another scenario, what if 52 shot much worse than 50.9 at distance?
 
What you're proposing is not negative testing.

Negative testing is a method of testing an application or system that ensures that the application is according to the requirements and can handle the unwanted input and user behavior. Invalid data is inserted to compare the output against the given input.
It's used because complex systems can produce unexpected results.

There isn't anything 'magic' about putting more rounds into a group that, in previous testing, did not display 'node like' results. If you did retest a charge that had displayed non node results and got really good groups - all that's going to tell you is you made execution errors in the first time.
 
Now don't be doing stuff I do...

I do shoot the scatter node intentionally to assess the rifle design and my ability to drive a mediocre rifle. When stuff goes sideways at a match, quitting is an option, but shooting what you have, to the best of your abilities is better.

I've won some matches with poorly tuned rifles. Go figure...

Bigger samples are a much better tool for evaluating loads and rifles. I've been fooled a lot in my journey as a load tuner. The final test of any load is a full 20 shot relay in good conditions at a competitive distance.
 
What you're proposing is not negative testing.

Negative testing is a method of testing an application or system that ensures that the application is according to the requirements and can handle the unwanted input and user behavior. Invalid data is inserted to compare the output against the given input.
It's used because complex systems can produce unexpected results.

There isn't anything 'magic' about putting more rounds into a group that, in previous testing, did not display 'node like' results. If you did retest a charge that had displayed non node results and got really good groups - all that's going to tell you is you made execution errors in the first time.


Nope. You're wrong. I deal with happy and unhappy paths daily. This is exactly a negative test case. It is the "Unhappy Path", where I am verifying I get an error when I use invalid inputs.

Happy path testing: good load test, small sample size results in good results in a 20 shot string at distance in good conditions

Then there is the unhappy path: scatter found with OCW, small sample size results in bad results at distance in good conditions
IE:
•bad inputs: scatter load
•error: bad group at distance
•expected result: bad inputs should throw an error

Negative Test:
Test Requirements: bad load shot at distance
Result must be: bad group
If you get a good group, your negative test failed

Now don't be doing stuff I do...

I do shoot the scatter node intentionally to assess the rifle design and my ability to drive a mediocre rifle. When stuff goes sideways at a match, quitting is an option, but shooting what you have, to the best of your abilities is better.

I've won some matches with poorly tuned rifles. Go figure...

Bigger samples are a much better tool for evaluating loads and rifles. I've been fooled a lot in my journey as a load tuner. The final test of any load is a full 20 shot relay in good conditions at a competitive distance.

That is an interesting strategy, to practice with a bad load to make sure you can deal with that situation when it happens...which will inevitably happen.

How big a variance have you found between your good node and scatter node when you do this? Your response was exactly what I was curious about.
 
Once the charge node is established,( stable) we want to know how wide that window will be and the way we do that is to test in smaller increments on both sides until a Tune goes away (scatter mode)
 

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