Accuracy: Spending Time on Things That Matter

[Walkalong]

We're mixing up rested vs non rested shooting here.

 

[denton]

For any process that is dominated by many small random sources of variation, the total random error will always be very close to normally distributed. Thus saith the Central Limit Theorem.

But, anyway, normality is overrated.

 

[Bill M.]

My thanks to those that posted the statistics. I simply did not read the original post well enough to see that the correct answer was there from the start. And I must have lost a lot of my statistical training. But I am up to speed now and concur with the math.

My full apologies to Denton, the OP.

I guess I get to serve as the "bad example" once again.

 

[denton]

My thanks to those that posted the statistics. I simply did not read the original post well enough to see that the correct answer was there from the start. And I must have lost a lot of my statistical training. But I am up to speed now and concur with the math.

My full apologies to Denton, the OP.

I guess I get to serve as the "bad example" once again.

Bad example??? Not at all!! It was a perfectly good question, one that I was happy to answer.

 

[Varminterror]

We're mixing up rested vs non rested shooting here.

We were described a 2moa rifle which for an undetermined reason shot an 8moa group... presumably in a short range context, as the claim that the group size and shape influence of 27fps SD is virtually undetectable...

 

[denton]

We were described a 2moa rifle which for an undetermined reason shot an 8moa group... presumably in a short range context, as the claim that the group size and shape influence of 27fps SD is virtually undetectable...

You're working very hard to avoid or obscure the point.

The reason for the 8" group was clearly explained. The rifle was being fired offhand.

I never said that the influence of a 26.9 FPS SD was virtually undetectable. What I said was, adding another 10 FPS to the standard deviation of a 25 FPS process produces a total SD of 26.9, and the effect of the difference between 25 and 26.9 is nearly undetectable. You have twisted my words.

And, finally, square root of the sum of the squares works for all real world distributions, not just the normal distribution

 

[GeoDudeFlorida]

Don't forget Heisenberg's Uncertainty Principle: There is inherent uncertainty in the act of measuring a variable of a particle in motion. The more aggressive the means of measuring a particle's state while traversing a plane, the more uncertain the observations become. The Uncertainty Principle is typically applied to quantum particles in single planes-of-motion but, the general conditions of the principle - that intrusive means of measurement introduce uncertainty - apply equally to Newtonian particles in motion, as well. Things like bullets... It is not possible to know at any given moment in time, with any certainty of precision, which variable or variables in a bullet's path, or which variable or variables in the bullet's movement along that path, is/are affecting its path or movement or to what degree. Even stop-action photography and digital radar/sonar cannot account for all variation at any given moment with no uncertainty. For one thing, we can't see what's happening inside the bullet.

 

[murf]

Because of the peculiar way that variation adds, you will NEVER make a big improvement in variation by fiddling with the less important variables. The ONLY way to make big improvements in variation is to find and control the major sources.

that is why i "liked" your post. reducing total variation is the name of the game here.

Square root (25^2 + 10^2) = 26.9 FPS. That is a small change, very hard to detect.

but it made a huge difference by shrinking groups from 2 moa to 1/4 moa.

switching to a 1/4 MOA rifle

that changes a whole bunch of other variables. better to use the same gun with both 2 moa ammo and 1/4 moa ammo. in this scenario the groups will shrink, i would think (even offhand @ 100 yards).

murf