Satterlee 10 Round Load Development

[A5BLASTER]

It looks like our definitions of terms are different.

Accuracy refers to how close the shooter can place bullets to the point of aim, and precision is the guns ability to shoot tight groups regardless of where they fall on the target.

"Better groups" for me in a work-up is precision - I am looking for the tightest group. Environmental conditions like wind are variables we try and exclude when focussing on a guns ability to fire ammunition. Wind affects accuracy but not precision. Shooters often use the term accuracy as an umbrella term when they are technically talking about precision. I do it all the time but right now we are parsing the concepts to get to the bottom of what we are really trying to do.

What hits targets and wins matches is a combination of precision and accuracy.

Your term "durable" seems to me to be consistency in precision. We expect when doing a work-up that the results are repeatable or the same every time, and will be into the future. In scientific experimentation this is called 'Reliability' and is one of the two key measures of experimental quality: Reliability and Validity.

Implied in precision is that results are repeatable, reliable. When I do a work-up, like Henka is saying we often are not controlling variables as well as we should. He rightly points out the risks of lack of reliability in these shooting work-up methods due to differences in case volumes, brass ductility and a host of other variables; some of this is our responsibility and some of it is down to the manufacturers quality control, or even factors beyond anyone's control. Also bear in mind that even if you can control all variables at the time of working up a load, that things are going to change; the gun barrel wears, the brass wears and gets replaced, different powder lots, shooting at different times of the year. In two years' time your favourite load might not be the best load.

I think you will find that Satterlee will be focussing on validity also and not just reliability.

Good post thanks Klem.

On a side note I took your method and ran some higher charges of my 123 eld-m load for my CZ that I didn't mess with before.

My load now gives 2636 average fps and 4 sd with a 13 es and shoots a easy 5 shot 1/2 group.

Useing your method I found a node at 29 grains that gave a sd of 2 and a es of 7 . Didn't have my calipers but will tommorw, I bet the 10 shot group was under 1/2 inch are dam close to it.

Will be rerunning it again tommorw.

[Klem]

A5,

Bloody Hell, I need to start taking my own advice!

[Harpoon1]

It looks like our definitions of terms are different.

Accuracy refers to how close the shooter can place bullets to the point of aim, and precision is the guns ability to shoot tight groups regardless of where they fall on the target.

"Better groups" for me in a work-up is precision - I am looking for the tightest group. Environmental conditions like wind are variables we try and exclude when focussing on a guns ability to fire ammunition. Wind affects accuracy but not precision. Shooters often use the term accuracy as an umbrella term when they are technically talking about precision. I do it all the time but right now we are parsing the concepts to get to the bottom of what we are really trying to do.

What hits targets and wins matches is a combination of precision and accuracy.

Your term "durable" seems to me to be consistency in precision. We expect when doing a work-up that the results are repeatable or the same every time, and will be into the future. In scientific experimentation this is called 'Reliability' and is one of the two key measures of experimental quality: Reliability and Validity.

Implied in precision is that results are repeatable, reliable. When I do a work-up, like Henka is saying we often are not controlling variables as well as we should. He rightly points out the risks of lack of reliability in these shooting work-up methods due to differences in case volumes, brass ductility and a host of other variables; some of this is our responsibility and some of it is down to the manufacturers quality control, or even factors beyond anyone's control. Also bear in mind that even if you can control all variables at the time of working up a load, that things are going to change; the gun barrel wears, the brass wears and gets replaced, different powder lots, shooting at different times of the year. In two years' time your favourite load might not be the best load.

I think you will find that Satterlee will be focussing on validity also and not just reliability.

Your right, being accurate and precise are two different things. I was thinking “precision” and meant that, when I wrote “accurate”. Slip of the tongue. So, yes, precise would have been a better choice of words in that context.

I still say, Satterlee’s main goal is finding the lowest possible SD’s, at the highest muzzle velocity, with the least temperature sensitivity, over the largest variation in charge weights, in the most efficient way possible. With absolute “Precision” being further down the list of requirements.

Which is exactly what I’m after in a hunting load. I don’t need precision as much as I do accuracy. And The Satterlee method is just a quicker more efficient shortcut to basically arrive at the same place you would using Dan Newberry’s OCW method. Which has reliably worked for me in the past.

YMMV.

[A5BLASTER]

A5,

Bloody Hell, I need to start taking my own advice!

I'm going to rerun it again today, to make sure it wasn't a fluke.

I typically choose 3 or 4 of the best looking shots from my pressure ladder to do my 10 shot sd and es testing, so never tested these higher loads with the 10 shot spreads for sd and es.

I might start testing more now just to see if it repeats what I seen yesterday with other loads I have worked up.

[Klem]

I still say, Satterlee’s main goal is finding the lowest possible SD’s, at the highest muzzle velocity, with the least temperature sensitivity, over the largest variation in charge weights, in the most efficient way possible. With absolute “Precision” being further down the list of requirements.

YMMV.

"YMMV" That's fine, we're just having a discussion.I am learning as much as everyone here.

So you are saying Satterlee's goal is not to find the smallest groups but the most consistent groups over time?

How can you say for sure that a particular load is the most consistent if you don't shoot multiple groups at all increments of the ladder and then compare? If the reply is that it's too many rounds and effort then you are relying on the generalisability of only 10 shots to a larger population of thousands of shots - the life of that barrel. That is an expensive risk to take don't you think? It also requires faith.

You can let Satterlee decide the load and then shoot only that load multiple times, and find they are pretty consistent. But another load might be more consistent. If you say that it is consistent enough for your purposes (hunting) then other loads in the ladder will likely be consistent enough too...and in that case you may as well go for the smallest, most precise load.

You logic is based on the premise that loads/increments which are inelastic on the load/velocity curve will be inconsistent over time. How do you know this without firing these other loads multiple times to confirm.

Just saying.

You've got me interested in loading up a ladder of multiple groups and contained within the data will be Satterlee. We can compare Satterlee against where the tightest group is and how consistent each recommended load is.

[Lemonaid]

Klem, adding to the mix now is the bullet jump testing from precisonrifleblog. https://precisionrifleblog.com/2020/04/0...ment-data/
Satterlee and friends now find the best bullet jump distance first, then do charge weight variations. Long story short is as they shoot up to 200 rounds a match, the lands would erode enough that they would be off their sweet spot before the match was over. So again to have a larger window of consistent loads they did a lot of testing. It's a good read, lots of data and graphs, I think it's up to four installments now.

[Klem]

Lemons,

Off their sweet spot in 200rds...Is that right? This sweet spot they are chasing is so fleeting that it is gone in a couple of shooting sessions. What are the chances we will even notice this in an AR15, made worse by using a bipod and cheap scope?

In F-Class we would be chasing the lands as the barrel throats wore. But, only firing 30rds a week it would take a year before it became an issue. By then people were buying new barrels anyway.

[Lemonaid]

A quote from the first section: https://precisionrifleblog.com/2020/03/2...velopment/
"in the last article, we discussed how quickly the lands of a barrel erode. While that is dependent on many factors, the measurements shared in the article showed an average of 0.004-0.007” of erosion every 100 rounds for popular mid-size cartridges used in precision rifle competitions.

Those two things seem to present a problem for those of us who might fire 100-200 rounds in a single match, because by the last stage our bullet jump could be 0.014” longer than it was on the first stage. If changing bullet jump by 0.002-0.005 inches can have a “dramatic” impact on precision, what will 3 times that much do?

Some of you may already be thinking you might start loading your 200 rounds of match ammo with increasing length. We just need to seat the bullet out 0.001” more every 16.67 rounds, right? Stop. Before we add yet another layer of complexity, what if we’re coming at the problem the wrong way? Knowing that we’ll be in matches that may require 100-200 rounds, maybe our priorities should be different than other shooting disciplines that are low round count or literally load their ammo at the range as they’re shooting. What if instead of looking for the one exact bullet jump that provides 100% optimal precision, we instead looked for the bullet jump that is the both forgiving in terms of bullet jump AND still provides good precision?"
There is too much in the articles for me to give short answers without the data and methodology they post. Be sure to read the comments sections as there are good questions and replies there.

[Harpoon1]

So you are saying Satterlee's goal is not to find the smallest groups but the most consistent groups over time?

You can “cut to the chase” 7:30 in starts Satterlee’s contribution.

https://youtu.be/O4K4l0KzRfg

[Klem]

Here's a work-up done yesterday with Satterlee embedded. 50 rounds fired at 100yd targets in ten increments of 1%.

All five rds fired per load fired at same point of aim (10 x 5rd groups).

It is 5 Satterlee's in a row, fired at targets.

Here they are graphed. You can see there are two to three 'accuracy' nodes per 10-shot ladder. Each Satterlee string produced different nodes which sinks the theory immediately. If however you combine all 13 nodes (bar graph, bottom right) you can average them out to three common nodes.

21.8 grains of H4895
22.7
23.0

Even the averaged nodes don't match the tightest group, 23.5gns. 23.5 is the best load I settled on a while ago so the results on target appear to be repeatable. There is no visual correlation between group size and elastic velocity ranges (bottom left graph).

On this occasion Satterlee did not work, five out of five times. I think the technique has more holes than Swiss cheese.

[ATTACH=CONFIG]16260[/ATTACH]

223 bolt gun
Bench rested
80SMK
100yd.
No wind
New Lapua brass
Lab Radar for velocity
On Target for group sizes.

[Lemonaid]

Klem, just out of curiosity, at what loads in your test did you get the best SD and ES?

[Klem]

Klem, just out of curiosity, at what loads in your test did you get the best SD and ES?

Lemon,

Here is a copy of the barrel data I keep in a digital diary.

[ATTACH=CONFIG]16261[/ATTACH]

• The first column of 15rounds was 15 warming/fouling rounds to settle the barrel. No MOA recorded as it was shooting steel.
  
• Note, the best group in the test is the same load as the fouling load. It is heartening that the previous work-up is repeatable.
  
• The powder 'AR2206H' is the same as 'H4895'. It's what it's called here.
  

Notice the Standard Deviation and extreme spread at the best group, 23.5gns. That suggests Satterlee works...and for a second I thought what a chump, it really does work. Hold on, looking across the SD's there's an even lower SD/spread, 22.3gns. Unfortunately, the group size for the best SD/spread is one of the largest. If I wasn't shooting at a targets and just going off velocities I might spend the rest of that barrel's life throwing large groups downrange not being any the wiser.

For full disclosure here are the groups, numbered from lightest to heaviest load;

[ATTACH=CONFIG]16262[/ATTACH][ATTACH=CONFIG]16263[/ATTACH][ATTACH=CONFIG]16264[/ATTACH][ATTACH=CONFIG]16265[/ATTACH][ATTACH=CONFIG]16266[/ATTACH]





.

[Lemonaid]

First klem let me acknowledge the great deal of work and brain power you have put into this, really great! I started the thread to gather information about the Satterlee method and how it works or dose not work for those that have tried it and the posts here have answered the call.
Let me now try to channel Satterlee to a small degree and take your data and play with it a bit.
In Satterlee's world he is more focused on hitting steel at long range (1000 yards plus) so the ES and SD are more important to him than absolute small groups at closer range. At some point in a long range trajectory a low ES load with average sized groups (at short range) will out preform a larger ES load that had a smaller group at short range. The variations in bullet velocity from a high ES load causing enough vertical variation to make a miss.
So he would see your node at 22.3 and see that it produced the best SD ES with your 5 round tests and the next step would be if he didn't like the group size would be to play with the seating depth to get that load to group as small as possible, then to try that load at long range (600 yards to 1000 yards) to verify that he can make hits with it.
So it might just be that if you used your superbly accurate 23.5 load for a competition on targets out to 600 yards you would score better than the 22.3 load but at 800 or more the 22.3 load would work better (imagine your data came from a 6.5 Creed).
This is all theory to me so far so I may be completely wrong! But the people that swear by it shoot a whole lot more than me and at a lot longer distance and are high in the rankings in the ELR game so I will give some credence that it can work.

[Klem]

That is an interesting hypothesis.

I've deleted the comment as I see where you are going with this...It is about bullet drop differences at long range caused by different velocities. We can still do a 'What-if' using the load data to see the difference between best SD and best 100yd group size.

I will run some numbers and amend this comment with the results soon

[centerfire]

The Satterlee method isn't intended to find the tightest group but to identify velocity nodes in the least amount of rounds possible. Your group size is irrelevant. Your spreadsheets still invalidate the process but your commentary on the group size is more of a sidebar. The next step should be finding the optimal seating depth to tighten the group assuming you found a velocity node. Based on your spreadsheet I'd probably change primers or powder because the SD's are high and loads .3gr above and below don't suggest a velocity plateau.

[Arkhangel5]

As an aside to this topic. Question for Klem.

Have you ever gone higher in powder charge with H4985 and this weight class bullet?

H4895 is my preferred powder for the .223 in 600yd F-class matches.

SY

[Lemonaid]

That is an interesting hypothesis.

I've deleted the comment as I see where you are going with this...It is about bullet drop differences at long range caused by different velocities. We can still do a 'What-if' using the load data to see the difference between best SD and best 100yd group size.

I will run some numbers and amend this comment with the results soon

Thinking back to some of Satterlee's comments on the 6.5 guys site he may have chosen your 23.5 over the 22.3 load for the better velocity or even the super accuracy, but maybe tested both out at long range to pick the winner.

[Klem]

I have done a 'What if' at 1K yards using JBM's online ballistics calculator. It's not real like the 100yd test but it is consistent if you believe the MOA drops it spits out.

[ATTACH=CONFIG]16272[/ATTACH]

In the scenario I have given the Satterlee load (the best SD/Spread) the best chance of winning by assuming the following;

1. That the slowest round is at the bottom of the group, the 6 O'clock position.
   
2. That the fastest round is at the top of the group, the 12 O'Clock position.
   
3. That the actual Best Group at 100yds was a statistical anomaly (unusually tight) and have made it the size of the next best group 0.329MOA@100yds.
   

Assuming a cone of fire will never diminish as range increases I have multiplied the 100yd group sizes by 10 to simulate 1,000yds. Then added the max possible vertical bias that differences in bullet velocity would blow the group out by. This is the difference between fastest bullet at 12'Oclock and slowest bullet at 6'clock.

Even with biasing Satterlee with the best possible conditions and replacing that great group at 100 with the next best group, the Best Group still wins the day.

Sure, different velocities will expand the group at 1K with a vertical bias but looking for the lowest Standard Deviations/velocity spreads is not the best predictor of 1K group size when you have actual 100yd group sizes to inform your decision. If you accept JBM's drop predictions, and assume both groups and velocity spreads are repeatable we can now say with certainty that Satterlee does not work in all situations. Unfortunately, you will never know when Satterlee is correct unless you shoot all loads at 1K, which of course renders Satterlee moot as a predictor.

And the idea you can do all this with only 10rds across chrono is as useful as an ashtray on a motor bike.

[Klem]

The Satterlee method isn't intended to find the tightest group but to identify velocity nodes in the least amount of rounds possible. Your group size is irrelevant. Your spreadsheets still invalidate the process but your commentary on the group size is more of a sidebar. The next step should be finding the optimal seating depth to tighten the group assuming you found a velocity node. Based on your spreadsheet I'd probably change primers or powder because the SD's are high and loads .3gr above and below don't suggest a velocity plateau.

Centrefire,

Well, at least we agree that Satterlee does not work in all situations.

And if you want to compound the validation by suggesting it is invalid because the OAL is not being tested and lots of different powders are not being tested then again, how will you ever know that the lowest SD/velocity spread produces the best results at 1K unless you test all of these other permutations across all other loads to produce the tightest groups at 1K?

Are you saying that because my SD's were not low enough that this somehow confounds Satterlee, and that Satterlee only works with single digit SD's? Surely, as long as all variables across all loads are equal that shouldn't matter. Yes, I could now tinker with powder and primers to tighten the SD's but how much of doing this is enough to turn Satterlee into a good predictor of best groups at long range? You can tighten SD's by tinkering with primer/powders but how does that guarantee Satterlee is now a better predictor of long range accuracy than doing the same tinkering and seeing the effects on a target at 100?

Tightest groups is not a sidebar, this is what you are trying to achieve at 1K, to give your ability to drive this around the target the best chance of winning. Finding the tightest velocity nodes with the lowest round count at the muzzle is not the aim of the exercise, it is the mediating variable to finding the tightest groups at long range.

As shooters we could start a discipline where we shoot across chronographs into the butts without targets and the winner is the one with tightest velocity spread. But that's not what Satterlee is currently used for. It is used to predict results on a target. Results on targets are measured in group sizes and our ability to place those groups on an aiming mark; Precision and Accuracy.

[Mad Charlie]

"And the idea you can do all this with only 10rds across chrono is as useful as an ashtray on a motor bike."

Thanks Klem, this has been my suspicion ever since I heard of the Satterlee method and thanks for your work.