Bad E-S's

[Forrest84]

So im kind of stuck figuring out why i have a lousy ES.
6.5 Lapua W/Lapua brass.
I have two nodes @ 40.7 grains and 41 grains
Below is a pretty typical read shot string
#1 - 2889
#2 - 2896
#3 - 2902
#4 - 2899
#5 - 2882
#6 - 2894
#7 - 2881
#8 - 2888
#9 - 2887
#10 - 2894
SD - 6.9
ES - 21

Brass is 3 times fired
I size the cases with a redding type s full length die shoulder bumped back 2 thou
I then run them through a LE Wilson Neck sizing mandrel
Ive been measuring powder through a chargemaster and then checking on a second scale to make sure there is no funny business going on with the scales and they match up perfectly.
I seat them with redding micrometer die. with around 4 thou jump from my seating depth test gave me .33 MOA.

Before winter set in down here it was at single digit SD and ES's and the same for my 6 BR but both had ES's shoot way up to the 30's and i cant figure out whats going on.

 

[rustyinbend]

Single-digit SD's and ES around 20 ... declare victory and shoot for tight groups, and for distance to true your BC.

 

[nn8734]

So im kind of stuck figuring out why i have a lousy ES.
6.5 Lapua W/Lapua brass.
I have two nodes @ 40.7 grains and 41 grains
Below is a pretty typical read shot string
#1 - 2889
#2 - 2896
#3 - 2902
#4 - 2899
#5 - 2882
#6 - 2894
#7 - 2881
#8 - 2888
#9 - 2887
#10 - 2894
SD - 6.9
ES - 21

Brass is 3 times fired
I size the cases with a redding type s full length die shoulder bumped back 2 thou
I then run them through a LE Wilson Neck sizing mandrel
Ive been measuring powder through a chargemaster and then checking on a second scale to make sure there is no funny business going on with the scales and they match up perfectly.
I seat them with redding micrometer die. with around 4 thou jump from my seating depth test gave me .33 MOA.

Before winter set in down here it was at single digit SD and ES's and the same for my 6 BR but both had ES's shoot way up to the 30's and i cant figure out whats going on.

What impact has this had on your ability to hit targets down range? Have you noticed a significant drop in hit rate that can be attributed to the delta in ES?

 

[bbhank]

What he said ^^^^^

I only look at SD's and anything is the single digits is great. if its 10,11,12 and shoots tight groups I'm good too!

 

[spife7980]

Quit looking at the numbers and look at the actual effects downrange.

Put some paper out and shoot it.

 

[918v]

That happens as the neck hardens. Some cartridges are more sensitive to this than others. You’ll have to correctly anneal the necks to get the ES back down.

 

[Buzzinga]

I've always considered SD of 7 or less to be pretty darn good. (approx 20 shots or so)

 

[Doom]

If you were to shoot enough rounds your ES would ultimately exceed 6x you standard deviation. That is not a problem it is a fact. As others have said, you seem to have a good load and process. Go shoot it.

 

[Forrest84]

Yeah i could be getting sucked into the chrono numbers, I havnt anealed yet, although i do have one so ill start the next go around. I looked at what that extreme high and low would do on the bollistic calc out to 1000 and its only showing .1 mil deviation in flight difference in total.
I have a 250 yard range at home and it prints real well on paper. I figured last night id call it good and just run it as it is in matches since im getting a late start in the season anyway. Guess well see what the bullit tells me at distance. I may not even be able to notice hardly at all.
Ill try to get out to tripple C in the next week or so and validate performance at distance.

 

[Sig Marine]

Are you new to reloading? A lot of guys on this forum would LOVE to have your numbers. But...as others have said, it's what happens on the target that matters.

 

[Forrest84]

yeah i have all of about 3 weeks of reloading experience lol

 

[kthomas]

I don't see a problem with those numbers.

What do you mean by "nodes"? Did you find these with a velocity ladder, a la "satterlee method"?

 

[Raufoss]

Powder humidity

 

[Feniks Technologies]

For anyone interested who doesn’t know how Standard Deviation distribution works:

This is what a 5sd and 2950 avg MV really means.

An ES of 30

~ 68% of shots = 2945 - 2955
~ 94% of shots = 2940 - 2960
~ 99% of shots = 2935 - 2965

I rounded 99.7% down purposely to illustrate that you still have a small chance for your 5sd to have a 40es or more at times when you have that 0.3% kick in.

Basically, a sub 20 ES requires a 3sd.

A single digit ES requires a 1.5 or less SD.


What that translates to:

A sub 30es is all but impossible long term.

 

[Forrest84]

I found the Nodes with the Satterlee method. I considered Powder humidity due to a flaw in my handling methods but i keep silica packs in my powder after its been opened, I also putt the powder back in the container after each session. I also opened a fresh powder container and re shot everything from scratch with the same result, so i crossed powder off my list.
Below is the results of one of my sessions right before things had a decline. the brass is still the same batch of twice fired lapua i have.

#1 - 2905
#2 - 2904
#3 - 2906
#4 - 2913
#5 - 2915
#6 - 2916
#7 - 2913
#8 - 2913
#9 - 2909
#10 - 2914
SD - 4.4
ES - 12

Im going to run with it what i have at this point but i cant help but rack my brain how i go from the above to what i showed up in the opening post.

This happened with both of my guns at the same time and the other had virgin brass.

 

[kthomas]

Satterlee method is your first problem.

That method uses sample sizes that are statistically insignificant, you are not finding any "nodes" with that method unless you come across them through dumb luck.

 

[Forrest84]

For anyone interested who doesn’t know how Standard Deviation distribution works:

This is what a 5sd and 2950 avg MV really means.

An ES of 30

~ 68% of shots = 2945 - 2955
~ 94% of shots = 2940 - 2960
~ 99% of shots = 2935 - 2965

I rounded 99.7% down purposely to illustrate that you still have a small chance for your 5sd to have a 40es or more at times when you have that 0.3% kick in.

Basically, a sub 20 ES requires a 3sd.

A single digit ES requires a 1.5 or less SD.


What that translates to:

A sub 30es is all but impossible long term.

presently wrapping my head around this but i have to get up every couple minutes so im not ignoring your informative post, im very interested.

 

[nn8734]

I found the Nodes with the Satterlee method. I considered Powder humidity due to a flaw in my handling methods but i keep silica packs in my powder after its been opened, I also putt the powder back in the container after each session. I also opened a fresh powder container and re shot everything from scratch with the same result, so i crossed powder off my list.
Below is the results of one of my sessions right before things had a decline. the brass is still the same batch of twice fired lapua i have.

#1 - 2905
#2 - 2904
#3 - 2906
#4 - 2913
#5 - 2915
#6 - 2916
#7 - 2913
#8 - 2913
#9 - 2909
#10 - 2914
SD - 4.4
ES - 12

Im going to run with it what i have at this point but i cant help but rack my brain how i go from the above to what i showed up in the opening post.

This happened with both of my guns at the same time and the other had virgin brass.

Stop getting so wrapped around the axle with SD and ES!

I dont even bring my LabRadar wirh me shooting anymore as its a pain to lug around and is only needed if/when anomalies show up down range.

Spend time shooting and validating your drops on targets so you can begin building your DOPE book. If weird shit starts happening downrange, then trouble shoot.

The differences in your set of SD/ES numbers are immaterial in terms of influencing hit probability. Not to mention, you have way too few shots in each sample to make useful population inferences

 

[Feniks Technologies]

presently wrapping my head around this but i have to get up every couple minutes so im not ignoring your informative post, im very interested.

It’s no prob.

As mentioned above, your ES will be ~ 6x your SD 99.7% of the time.

And generally speaking, you need ~ 30 shots to have close to a 98% confidence in your data.

Also, as mentioned above, if you don’t anneal each firing, your numbers can start creeping. Along with a host of other variables.

Just understand how the data actually works and don’t get your head wrapped around when something that’s inside the noise shows up.

 

[6.5SH]

I found the Nodes with the Satterlee method. I considered Powder humidity due to a flaw in my handling methods but i keep silica packs in my powder after its been opened, I also putt the powder back in the container after each session. I also opened a fresh powder container and re shot everything from scratch with the same result, so i crossed powder off my list.
Below is the results of one of my sessions right before things had a decline. the brass is still the same batch of twice fired lapua i have.

#1 - 2905
#2 - 2904
#3 - 2906
#4 - 2913
#5 - 2915
#6 - 2916
#7 - 2913
#8 - 2913
#9 - 2909
#10 - 2914
SD - 4.4
ES - 12

Im going to run with it what i have at this point but i cant help but rack my brain how i go from the above to what i showed up in the opening post.

This happened with both of my guns at the same time and the other had virgin brass.

A desiccant alone is the wrong approach regarding humidity, look at the 2-way humidor packs.

How does humidity affect powder?

You may have heard about a relationship between humidity and bullet velocity either in a book, on a reloading forum, or from a crusty benchrest shooter right after saying they get better ES/SD&#821…

chronoplotter.com

 

[Forrest84]

A desiccant alone is the wrong approach regarding humidity, look at the 2-way humidor packs.

How does humidity affect powder?

You may have heard about a relationship between humidity and bullet velocity either in a book, on a reloading forum, or from a crusty benchrest shooter right after saying they get better ES/SD&#821…

chronoplotter.com

Yeah i tried 32% and 62% as well before just defaulting to the regular silica packets

 

[babyguppy]

@Forrest84 what's the relative humidity with pure silica?

 

[Forrest84]

I’m not sure honestly maybe 10%?

 

[m1ajunkie]

Satterlee method is your first problem.

That method uses sample sizes that are statistically insignificant, you are not finding any "nodes" with that method unless you come across them through dumb luck.

What is the suggested alternative to this method? Load several rounds at each charge in a ladder test?

 

[kthomas]

What is the suggested alternative to this method? Load several rounds at each charge in a ladder test?

I ladder test just to get an idea of velocity per charge weight and where pressure may begin.

From there, I'll have an idea of what velocity I want to shoot my projectile, and I will load up several rounds (5+), of each charge weight that's around that velocity. I run them all over the chrono and see what produces the lowest SD/ES.

However, I've found through a lot of testing with my 6BRA that you can load most anything and have good SD/ES. One day, one charge weight may do a bit better than another, but averaged out they all perform really similarly.

What's most important is using quality components, and being consistent. I can load anywhere from 29.0 grains of H4894 to 30.8 grains in my 6BRA, and it will all perform relatively the same, just at different velocities.

 

[m1ajunkie]

I ladder test just to get an idea of velocity per charge weight and where pressure may begin.

From there, I'll have an idea of what velocity I want to shoot my projectile, and I will load up several rounds (5+), of each charge weight that's around that velocity. I run them all over the chrono and see what produces the lowest SD/ES.

However, I've found through a lot of testing with my 6BRA that you can load most anything and have good SD/ES. One day, one charge weight may do a bit better than another, but averaged out they all perform really similarly.

What's most important is using quality components, and being consistent. I can load anywhere from 29.0 grains of H4894 to 30.8 grains in my 6BRA, and it will all perform relatively the same, just at different velocities.

Good deal, appreciate the comments. I'm fighting some brutal ES/ SD numbers on a 300 PRC even though I feel like I'm loading in the node I found in ladder testing. Starting to wonder if my single round ladder testing is part of my challenge.

 

[kthomas]

Good deal, appreciate the comments. I'm fighting some brutal ES/ SD numbers on a 300 PRC even though I feel like I'm loading in the node I found in ladder testing. Starting to wonder if my single round ladder testing is part of my challenge.

The single round ladder testing is not really giving any useful information when it comes to finding any "nodes".

It's amazing how much traction the "Satterlee method" got, and how many prominent figures promoted it. I even did it for a time when I first got into reloading. I think its one of the worst reloading myths that has been propagated in recent times.

 

[m1ajunkie]

The single round ladder testing is not really giving any useful information when it comes to finding any "nodes".

It's amazing how much traction the "Satterlee method" got, and how many prominent figures promoted it. I even did it for a time when I first got into reloading. I think its one of the worst reloading myths that has been propagated in recent times.

Oh I've bought in hook line and sinker and now I'm trying to figure out a different method I can use to see if I can improve my load performance.

 

[nn8734]

Oh I've bought in hook line and sinker and now I'm trying to figure out a different method I can use to see if I can improve my load performance.

If im familiar with a cartridge and set of components ill just pick a charge based on desired velocity that I know is safe and make a few test groups with diff seating depths, usually .02” increments starting at .020 off the lands and usually go to .080.

Otherwise ill do an OCW then seating depth if a node is obvious on the target. Ill take velocity once im doing seating depth testing to get “starting” velocity that i can plug into a ballistic calculator then true at the shooting spot w/ KD targets.

I also used to do the ladder until I realized the so called flat spot shifted around when subsequent ladders were done using the same components.

 

[Forrest84]

So I went out to the range and was able to do 300 yards on paper and 450 on steel.
I did 4 5 shot groups all pretty close to the same result as below.
Not what I was hoping for but I fucking hate shooting on benches and the mirage was real bad and my dumb ass kept the mag up high for some reason even though I know better but I’ll run it none the less

 

[Forrest84]

Just realized the black pasties I’ve been using on my targets as the 1” reference for the app is actually .93… I erased it and uploaded the corrected photo

 

[Barelstroker]

Oh I've bought in hook line and sinker and now I'm trying to figure out a different method I can use to see if I can improve my load performance.

The 1st thing you can do is to come to the realization that NO rifle shoots A particular group size, no matter what you do, the rifle/shooter system will always shoot within a particular range most of the time.
The 2nd thing to do is to realize that most of the claims you've heard & read are cherry picked & are not representative of reality over hundreds of shots.
Contrary to popular understanding, when developing a pet load, you are not taking a group size of say 1.7MOA down to 0.5 MOA. The true goal is to reduce the average dispersion of the group size or, reduce the % of the number of the outer dispersion.
A good analogy would be changing the choke on a shotgun. If you change from a cylinder choke to a 3/4 choke, you still see pattern dispersion but it's a smaller dispersion. Rifles are exactly the same, one shot at a time. It's that simple.