ES & SD NUMBERS WITH ACCURATE LOADS

[DaveTooley]

So what have you all figured out to cause a fier in your examinations of culprit cases?

Yes inquiring minds want to know.

 

[Ned Ludd]

One thing is certain...you won't learn ANYTHING if you throw the case away before even examining it.

 

[dmoran]

Yes inquiring minds want to know.

Except for moral of reasoning, guess no inquiry reply for our interest.... lol
We'll just have to live with what we know for the reasons !.!.!

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[brxbrad]

I always take those cases home for examination. If you don't, you might never figure out what was wrong /different about that case, which might allow you in the future to cull those cases BEFORE ever firing any low 9s.

I spoke in error, they sometimes do make it home....

 

[SGK]

Adam would say the Shotmarker's velocity measurement error SD is almost good enough for load development, well behind the low error SD of the Two Box Chrono.

To the OP, dispersion on target at a defined distance and muzzle velocity ES/SD are two different things. For the former, there are many ways a set of bullets can arrive at close to the same point (or otherwise) on paper for a fixed distance. However, for that dispersion to extrapolate (or interpolate) over a range of distances will require good velocity ES/SD. In the end it's a compromise across both.

 

[SGK]

In my mind SD equates into vertical spread at long distances.

I always wonder where this assumption comes from. So many people here base decisions on this assumption but is it really the case? Sure we know that all-else-being equal a higher velocity shot will carry more vertical to the target. But everything else isn't equal. Barrel harmonics don't just 'operate' in the vertical plane.