Skip to main content ↑ ↓
Topic: 10 shot ladder test Scott Saterlee (Read 497 times) previous topic - next topic

10 shot ladder test Scott Saterlee

On the recent topic about nodes I had commented about an article I had seen on the 6.5 guys page a few years ago.  The article talked about the velocity of the bullet leaving the barrell was the reason for the node and barrell harmonics,.not the powder that produced that velocity.  I had tried to find the article, but the 6.5 guys home page.seems to be gone.
I kept looking and found some info on the article.  If you will Google  "10 shot ladder test sniper hide august 2017"  you can see that info.
The research was by Scott Saterlee, who also was using and promoting the 10 shot ladder test. 
Just thought it was interesting and that some of you might want to look it up.  I believe Scott is very knowledgeable.
Anyway, neat topic.

Re: 10 shot ladder test Scott Saterlee

Reply #1 –
Scott is very knowledgeable and one hell of a special ops warrior. I have nothing I can post to back this up, but rumor has it that even he is now not confident in this 10 shot load development protocol for the average reloader.

The problem arises from the standard deviation that is inherent in a specific charge weight. There is no way to assess SD from a single shot and three shots of the same charge weigh barely brings to light the velocity variability associated with a specific set charge. Averaged velocity from three rounds of the same charge weigh will better predict true velocity than will the result of a single shot.

Therefore, if you are developing a load based on velocity measurement, your assessment will be much more accurate looking at the average velocity of 3 rounds of the same charge and doing this with each incremental increasing charge weight.

So - if you are going to develop incremental velocities from 3 rounds for each charge why limit your data input to just velocity measurements. You will get so much more insight by running an OCW or 3 shot ladder test while recording the velocity of all your shots. By doing this you get to see the 3 shot grouping patterns of each charge weight and the velocity pattern as the range of charge weights are shot.

I’m not trying to change anyone’s mind about how they do their load development. However, the bottom line of my point of view is - one shot for one charge weight does not give you trustable/accurate info and in fact may be very misleading. The 10 Shot Satterlee gained popularity because it IS right sometimes, it is quick to run, and cheap with the few amount of rounds required. Some guys say it works great for them - sooner or later it will burn them with misinformation and lead to some tail chasing during load development which can be expensive and frustrating. For me, I want to do it right the first time.

Re: 10 shot ladder test Scott Saterlee

Reply #2 –
Jerry, I agree with you.  Since using the Labradar, it has become pretty clear that the statistical variation of a single shot can't be reliably counted on for load development.  I have for the past couple years now been using 5-shot groups for my ladder development.  Now this has the downside of putting more rounds down the barrel and it is hard to consistently shoot a good 5-shot group but I believe that it is a better representation of the load.  It is also great practice since in competition, the ability to put a 5-shot and a 10-shot group together is kind of important.
Bob
If everything seems under control......you're just not going fast enough

Re: 10 shot ladder test Scott Saterlee

Reply #3 –
i have had good luck with the satterly method... every load i have come up with in the last couple years has came from the 10 shot ladder method...early on i would also ocw test against it to verify what i was seeing in the numbers and the numbers were telling me the same thing the ocw test was showing me... i have also struggled with the satterly method on a couple carts... one in paticular  was my 280 ai... the numbers would be there but the gun just wouldnt shoot.... i went back to a ocw test and it would show the same node as the 10 shot
ladder but the gun just wouldnt shoot small .. did this with 2 different bullets and 4 different powders.... i thought maybe that was just as good as the gun was capable of shooting... decided to try one more bullet... 4 grains lighter than i had been trying and the gun came alive... so theirs a bit of tail chasing no matter how you go about testing in my opinion till you find the right combination of components for your gun...  


Edit) i should add to this.. do i think this is for everyone.. no i sure dont.. and for the guys and gals just getting started in developing loads i would recommend  forgetting about the chrono and velocities to start with.. to do proper ocw test and learn what the target is telling you.. the targets dont lie...
Grant

Re: 10 shot ladder test Scott Saterlee

Reply #4 –
I ran a 3-string, 10-shot Saterlee a while back just to see if it's something I could believe in for myself. I ran this post auto trickler so I feel pretty good about the charge weights. My goal was to see if any, or all of the strings would indicate nodes. I also looked at the ES/SDs across the 3 strings just to see how consistent the strings were per charge weight. Knowing what I know now, this rifle has a nice node centered around 41.7 gr, and another one around 41.3 gr. The question is, do any of the shot strings indicate those nodes?


Chris,
Retiring end of Q2-2021 :)

Re: 10 shot ladder test Scott Saterlee

Reply #5 –
Yes. I would say your 41.7-41.9 node is showing up in that chart. One thing I didn’t say in the earlier post is that when you are in a node the velocity flattens as Scott has shown with his test, but it  also seems that SD lessens which is helpful in seeing the flatter part of a velocity curve. If you combine velocity, with SD, AND 3 shot groupings you have data that should cross reference for selection of the most stable node. You just are not going to get that (3 way)co- supporting data from 10 single shots up a charge weight scale. First of all you don’t see a tightening of SD - there is no SD with a single shot. Second of all you don’t see any target grouping - there is none with a single shot.
Of all three parameters: velocity, SD, and grouping, it’s the grouping that lets the target tell you what is happening. Of all three, it’s the most reliable in my opinion.

In summary, I don’t think Scott intended his test to be a definitive node development test. It is a short cut to a guess. If used that way, I think it’s valid. If it is used as the sole method of node development, it is frequently invalid.

Re: 10 shot ladder test Scott Saterlee

Reply #6 –
 :D i just did this 10 shot ladder last weekend.. i picked 42.6 for my charge and it was super close.. this morning i seated the bullets .005 deeper and heres the results.. cloudy damp conditions mid 50's 140 amax .. hornady cases ..100 yards.. just 3 shots.. i will see how they act at 300 and 430 when it dries up a little but i suspect they will do well..

Guess its luck.. 😁
Grant

Re: 10 shot ladder test Scott Saterlee

Reply #7 –
In addition to using 3 rounds, another addition I made to Saterlee's test was to look at the SD's and ES's across multiple groups.  Usually a low SD for a load is also low when compared to the loads next to it.  This helps with finding wide nodes that are resistant to variations.  Saterlee does this by looking for places where the graph goes flat between loads, but I found that doing the statistics worked better for me as the graph is not always so clear.

The pictures below show the change to the chart.  I don't recommend those loads.  The charts are just to provide an example of the statistical method.

Re: 10 shot ladder test Scott Saterlee

Reply #8 –
I think I could have pulled the 41.7 node from shot strings 1 and 3, string 2 is so linear I don't know if it would have told me anything.

Therein lies the rub, if I was lucky like Grant :) and shot 1 or 3, good to go, if I'd shot string 2 I'd be flustered.

There's also another element to consider with a limited sample size; everything has to go just right. No duds, no chronograph dropped shots, etc.
Chris,
Retiring end of Q2-2021 :)

Re: 10 shot ladder test Scott Saterlee

Reply #9 –
Quote from: gman47564 on
:D i just did this 10 shot ladder last weekend.. i picked 42.6 for my charge and it was super close.. this morning i seated the bullets .005 deeper and heres the results.. cloudy damp conditions mid 50's 140 amax .. hornady cases ..100 yards.. just 3 shots.. i will see how they act at 300 and 430 when it dries up a little but i suspect they will do well..

Guess its luck.. 😁

Damn Grant! Is that muzzle blast on that paper target?

Re: 10 shot ladder test Scott Saterlee

Reply #10 –
lol..... you know it is!!!... no it has rained all night here and even though i use a thick card stock paper it is wet.. if i was to push that little flap down where it has blowed out the group would look smaller... the brown speckles on it is from where i rode the four wheeler out there and splashed mud up on it i guess... that was shot from the comforts of my man cave out the window...
Grant

Re: 10 shot ladder test Scott Saterlee

Reply #11 –
From my personal experience in shooting my 5-shot ladders, I first and foremost use the target group as my primary indicator.  I then use MV and flat spots on the curve to provide some re-enforcement/confirmation and width of the node.  It has been observed by several on this forum, there are some MV's that seem to be sweet spots....so if I see a good group and it is at one of these, that is a pretty good confirmation.  As for SD/ES, I have found these more a reflection of my loading consistency versus a node.  I have shot a ladder with some great SD/ES values but they didn't group worth a darn.  For me it tells me how I did at the bench more than if I'm at a node.  But I will concede that there seems to be a loose correlation between lower SD/ES and a node.....but not always.
Bob
If everything seems under control......you're just not going fast enough

Re: 10 shot ladder test Scott Saterlee

Reply #12 –
I have noticed a correlation when I did 9mm and 357 mag velocity node tests. My best groups were always, ( one exception ) the load with the least spread. I only used a 5 shot test string for each charge weight. I'm sure if I revisited it now, I could do a bit better, but the CZ Shadow shoots well and my Ruger GP 100 shoots deadly.

Re: 10 shot ladder test Scott Saterlee

Reply #13 –
The part that was interesting to me wasn't the 1 shot ladder. Myself, I start with 3 shot ladder
The part that was interesting to me is his conclusion that the powder used didn't matter as long as he was.getring the same muzzle velocity from the bullet.  Go back and look at that part of the article.  That is interesting.

Re: 10 shot ladder test Scott Saterlee

Reply #14 –
Yep it is an interesting observation. It seems that the different pressure curves created by powders with different burn rates would cause different barrel harmonics and this different results. There is still a lot about internal ballistics that I would like to understand better.