What's causing these ES numbers? Help me analyze, please

[devldogs55]

Thanks for the additional help. Tonight I'll load up some rounds to test seating depth and see if it likes something better. I gave the 175RDF a .030 jump. The actual group ended up being a .045 when I measured with calipers.. so I have a feeling I can find a sweet spot for jump that will shrink that group even more. If not - this is a steel plate whacker - so 1/2 moa ain't bad.

 

[TheGerman]

If/when your S/D is less than 10, you're chasing a rabbit hole.

At that point, the SD variation is just noise. You will generate more inaccuracies from breathing, trigger pull, parallax, atmospheric changes and mirage at that point then you ever will from a S/D of <9.

This is how you hear of those people that load a round, only to change parts and load some more, change it again, load more, and then have their barrel shot out before they settled on some unicorn bullet magic. At some point you're going to stand in your reloading area and get a barometric pressure reading to make sure your powder won't be too damp.

My suggestion is to get a power regulator for your chargemaster. I got one and it went from being +- .2 grains to being dead on constantly to the point that I don't even bother checking weights anymore after its set up.

If you seriously want to keep going down that hole, sort your bullets in lots of bullet weight and bearing surface.

 

[GhengisAhn175]

Stop devildog. If it ain't broke, don't fix it lol...

seriously. Go shoot your load at distance to verify.

Try 300 yards for groups, further if able but 300
should be a good distance.

 

[McCrazy]

I definitely was not taking the pan off and putting it back on, and it sounds like that was causing a lot of variation. I did do that once I got the Gem Pro, though.

Tyler, I don't think Winchester anneals factory brass.

Anyhow. I found one load that performed very well today. 50.0gr, Avg: 2698, SD: 5.4, ES: 12 and group was about .3". No pressure signs, no sticky bolt lift etc... I'll play with that some more tomorrow.

So you don't blow yourself or anyone else up, you have said 50 grains a couple times. What you mean is 45 grains. This could be a very costly mistake if you make it while loading instead of typing.

 

[McCrazy]

Alright, I've pulled all remaining bullets and re-tooled here. I just received my Gem Pro 250, and while it's not the top of the line necessarily - it sure pointed out a huge spread in charge weights that the Charge Master just doesn't account for. What I thought was a lot of 30 rounds with 44.8gr was actually anywhere between 43.6gr and 45.4 gr. Talk about some major ES! I pulled all 30, and ran them through the sizing die again with an expander ball on there. I am now running .002" neck tension, and I am confident the powder charges are within 1 or 2 kernels of where I wanted them. I've got 5 rounds each of 44.0/44.2/44.4/44.6/44.8/50.0 to try out, and I'm on my way out to the range within the next half hour. I'll be sure to post results when I'm back.

You also stated 50 grains here. Pattern analysis indicates you meant 45.0 grains.

 

[Downzero]

ES and SD are absolutely linked, by the theory that renders SD relevant to statistical analysis. SD isn't just a mathematical calculation--it's also related to a probability function that defines where the observations should be within a normally distributed data set.

95% of observations from any sample should be within 2 standard deviations of the mean. 99.9+% should be +/- 3 standard deviations. Tighter SD will create a situation where 3 standard deviations from the mean is a smaller number, which makes for a smaller extreme spread.

There may be a way where he can tighten up his variations, which will result in both smaller sample SD and smaller ES.

I understand what you're trying to say, but it is inconsistent with how the theory works. With a large enough sample, you SHOULD see variations in velocity like you're seeing. That's what it's called INFERENTIAL STATISTICS. The whole point is to be able to come up with a theoretical amount of "acceptable" variance from the statistics studied.

 

[Downzero]

If/when your S/D is less than 10, you're chasing a rabbit hole.

At that point, the SD variation is just noise. You will generate more inaccuracies from breathing, trigger pull, parallax, atmospheric changes and mirage at that point then you ever will from a S/D of <9.

This is how you hear of those people that load a round, only to change parts and load some more, change it again, load more, and then have their barrel shot out before they settled on some unicorn bullet magic. At some point you're going to stand in your reloading area and get a barometric pressure reading to make sure your powder won't be too damp.

My suggestion is to get a power regulator for your chargemaster. I got one and it went from being +- .2 grains to being dead on constantly to the point that I don't even bother checking weights anymore after its set up.

If you seriously want to keep going down that hole, sort your bullets in lots of bullet weight and bearing surface.

This is my point exactly.

 

[devldogs55]

You also stated 50 grains here. Pattern analysis indicates you meant 45.0 grains.

WOW Yeah.. not sure what made me say that.. but you're right. 45.0 grains.

 

[devldogs55]

As far as the rest of load development. I'll definitely test the load out more. I see what you guys are saying.. I just have a hard time accepting the fact that I randomly chose .030 off the lands was perfect right from the get-go. I'm new to secant ogives and I'm not even sure if the RDF could be considered a hybrid or not.. but it seems that guys are finding seating depths to be a little finicky.

 

[07yzryder]

random but did you spray your chargemaster down with antistatic? mine is nowhere near that off. even so I would call RCBS they should send you a new one.

 

[CMH]

If/when your S/D is less than 10, you're chasing a rabbit hole.

At that point, the SD variation is just noise. You will generate more inaccuracies from breathing, trigger pull, parallax, atmospheric changes and mirage at that point then you ever will from a S/D of <9.

This is how you hear of those people that load a round, only to change parts and load some more, change it again, load more, and then have their barrel shot out before they settled on some unicorn bullet magic. At some point you're going to stand in your reloading area and get a barometric pressure reading to make sure your powder won't be too damp.

My suggestion is to get a power regulator for your chargemaster. I got one and it went from being +- .2 grains to being dead on constantly to the point that I don't even bother checking weights anymore after its set up.

If you seriously want to keep going down that hole, sort your bullets in lots of bullet weight and bearing surface.

What kind of power regulator are you running?

 

[devldogs55]

Yesterday I messed around with the Charge Master a little and threw a couple dozen charges and weighed them on the Gen Pro. It was much more accurate than those charges from the rounds that I pulled. I'm fairly confident that the issue same when I trickled up.

I did did not remove the pan and then re-weigh when I was trickling up to my target, and I was trying to get .02-.04 kernel accuracy out of a scale that isn't capable of that.

I am also interested in the power regulator you are running.

 

[spife7980]

I run my scales though a trip light isobar as that's what everyone was recommending on accurate shooter