Thread: Testing a conventional approach to load development

Originally Posted by gimp

Thanks for reporting back. Can you post the targets?

I don't think it's terribly surprising - even if one is a believer in seating depth changing precision, the TMK is a tangent ogive bullet and not believed to be sensitive.

I've posted before that the order of effect size when changing variables, in my view, is something like this (gaps indicative of relative importance) :

Barrel quality (get a good barrel, properly chambered)



Bullet quality

Powder choice and how it interacts with specific bullet and barrel
Brass quality











--------unproven to be an effect-------------------
Any tuning of powder charge or seating depth






I'm not sure I believe there is such a thing as a genuine 0.5MOA rifle - using the definition of precision that refers to the full dispersion of the true cone of fire. I have yet to see any evidence that such a thing exists. Certainly in practical terms, the effect size of shooter error swamps rifle precision in the noise and no-one could actually take advantage of it in a hunting scenario

I didn’t keep the targets, but what I will do is take a few photos of the 10 shot groups that hopefully will be happening in the next week .
How do I get one of those apps that everyone seems to be using to measure their groups and get the mean radius info etc ?

Originally Posted by Ground Control

I didn’t keep the targets, but what I will do is take a few photos of the 10 shot groups that hopefully will be happening in the next week .
How do I get one of those apps that everyone seems to be using to measure their groups and get the mean radius info etc ?

Hornady 4DOF app, pay $4 for group analysis

Originally Posted by whanahuia

So given all that. Are we not back too looking for a rifle that constantly groups 3 or 5 shots together close too our desired POI?

If it actually does this, and you have actually checked meaningfully that it does this - you have collected a large sample size of data with reference to a fixed point.

This is what I recommend.

I just recommend doing it more efficiently so that you get the information immediately, and analysing it with a view to understanding whether it meets clearly set requirements or not.

I think the key as you say, is getting the best barrel/rifle combo you can afford. It's for most a moot point after that, as Id dare say most people can't go selling and buying if its not quite what they hoped for.

Taking extreme notice due too this thread, I have noticed a very slight bias towards the left of centre in my groups, and have moved 1 click right due to that. But reality is if as you say, human error is accounted for, it's in reality only a 4cm error at my self imposed max shooting distance. Hardly the factor that would be responsible for a bad hit.

Originally Posted by whanahuia

I think the key as you say, is getting the best barrel/rifle combo you can afford. It's for most a moot point after that, as Id dare say most people can't go selling and buying if its not quite what they hoped for.

Taking extreme notice due too this thread, I have noticed a very slight bias towards the left of centre in my groups, and have moved 1 click right due to that. But reality is if as you say, human error is accounted for, it's in reality only a 4cm error at my self imposed max shooting distance. Hardly the factor that would be responsible for a bad hit.

Actually you would be better off with your zero 1 click (1/4moa or 0.1mil) left of center as the spin drift will be to the right and the bullet will be almost exactly center by 400m.
So personally if it is 1 click left at 100m it is a perfect zero for my rifle setups.

Originally Posted by Ground Control

I didn’t keep the targets, but what I will do is take a few photos of the 10 shot groups that hopefully will be happening in the next week .
How do I get one of those apps that everyone seems to be using to measure their groups and get the mean radius info etc ?

I use Range Buddy on android. It is a free app. Ive used it for 4years. It accurately measures mean radius in mrad also.

I ended up finding sub moa free on IPhone seems alright no tutorials like ballistic X so takes a little figuring out ballistic X wanted a subscription to measure mean radius I was about to get hornday for $10-$11 dollars then read the above so looked for a free IPhone version seems to work well

@Kelton
Yep thats the identical app but for iPhone.