10 Shot Ladder test validity.

[maggitas]

I was wondering if anyone has tried the 6.5 guys 10 shot ladder test and if it worked for them.



Identifying a consistent and accurate load for your precision rifle while improving the overall efficiency of the load development process is a laudable goal. The 6.5 Guys met with Scott Satterlee to discuss and explore a technique he calls the “10 Round Load Development Ladder Test”. This is a load development approach he has refined to quickly identify accuracy nodes with only 10 rounds. Additional cartridges are then loaded to test and confirm these accuracy nodes. Scott’s approach really interested us as load development has traditionally been a time intensive and laborious process.

A lot of folks ask us if Scott’s methods are a replacement for OCW. When asked that question, Scott responds that his method uses a chronograph to get to the same answer as OCW. Prior to the availability of the extremely portable and accurate Magnetospeed, shooting groups as prescribed by the OCW method was the most practical way to arrive at an optimal load. Long story short, if you want to use the OCW method as promulgated by Dan Newberry there is absolutely nothing wrong with it. However, Scott believes his method is more efficient and arrives at the correct answer faster.

The following quote from Scott summarizes a key observation with load development, “Im not sure it is optimal charge weight at all but optimal velocity for the bullet weight that determines barrel harmonics. The reason I say this is because I can get the exact same great results in a velocity node using seven different powders. As long as I keep the bullet going the same velocity from powder to powder I get the same result. Powder charge may be slightly different but as long as I’m in the velocity happy place for that bullet and my cartridge, powder is secondary.”

Scott’s method is predicated on the shooter having their reloading techniques dialed in. After the release of the video, we had a number of viewers ask us what Scott does to perfect his reloading technique. We can tell you from personal experience that we have adopted many of Scott’s techniques and they work:

• Brass makes a big difference. Buy good brass and be done with it.
• Get a good chronograph. From a convenience and accuracy standpoint, theMagnetospeed is hard to beat.
• Sort your brass by lot and the number of times they have been fired. We can’t tell you how many inquiries we get from folks who purchase mixed lots of brass at the local outdoor store and wonder why they can’t find a good load.
• Annealing works. There was an experiment done by a reputable company and super smart guys, but the experiment was too limited to replicate high volume shooters. Take a look at our article on the AMP annealer where we discuss this.
• Powder weight is pretty important. Measure every single charge unless you are reloading in volume for a gas gun or pistol. A lot of folks use the RCBS Chargemaster and certain modifications can be made to really dial them in. This will be the subject of a future article.
• Find a load length that gets your bullets off the lands. A load that is jammed into the lands will not have durability and you will have to readjust them frequently. VLD bullets can be jump tolerant and extremely accurate well off the lands. The followingarticle from Berger Bullets confirms this.
• Remove primers as a separate step using a dedicated die such as the Lee Universal Decapper. We’ve conducted experiments where using the sizing die to decap increases runout.
• Use a mandrel instead of an expander ball. We’ve noticed less runout and lower SDs by doing this. Get a carbide mandrel so you can remove any burrs or imperfections after you remove the sizing lube from the brass. A mandrel also helps in conditioning the necks on virgin brass and avoids the need to full length size virgin brass.
• Pay attention to primer seating. Seat the primer until the anvil touches the bottom of the primer pocket and go ever so slightly further (.001″) to pre-stress the priming compound. This requires a refined sense of feel that can take some time to develop. We’ve encountered shooters with dud rounds who claim “I’ve got some bad primers.” Almost without exception, they are not seating their primers deep enough.
• If running a compressed load, settle your powder. Check out our article on bullet seating.

Here’s a summary of Scott’s “10 round” technique as described by him:

“I start 1.5 grains below my max load and load 10 shells ascending by .2 gr. So for the Swedemoor, 50.0, .2, .4, .6, .8, 51.0, .2, .4, .6, .8, 52.0
Then I will shoot these over the chronograph and look for the nodes. A node will be a velocity flat spot where .4-.8 gr of powder doesn’t move the speedometer much. This example with Reloader 26 in my 6.5 Addiction with 140 RDFs, the flat spot is between 51.2 and 51.8 grains -velocity went from 3025-3033 fps. So, .8 grains of powder added a total of 8 fps. Therefore, the middle of my node is 51.5 grains.

Next I then load up 5 of the 51.5 grain load and shoot them over the chronograph and the extreme spread was 5 FPS. I have repeated this with H100V, H4350, 4831, 1000, Retumbo, RE 17,19, 22, 23, 26, wiN 760, 780, VV 160, 170, 560, 570 IMR 4451, 4955, 7828 and 7977. With all of these powders, 3020-3035 fps was an accuracy node without regard to the powder type.

Once I find the velocity node I load in the middle of it then fiddle with COAL until it shoots tiny groups with low low extreme spreads. You can have an accurate load at 100 yards that will not shoot past 600 yards because you have a high extreme spread. For me any extreme spread that is over 25 FPS is unacceptable no matter how small the group is at 100 yards. Even if I had a load that shot .1 moa at 100 yard yet had an ES of 30, I wouldn’t use that load for a match. I would take a .3 moa load that had a sub 10 fps extreme spread any day of the week because the load will not start to spread vertically past 600.”

 

[ballison]

I haven't used this method to develop a load from scratch, but after reading this a while back, I did use it to "confirm" my load. I shoot a 6x47L with the 105 hybrids & H4350. I'm on my second barrel, and both have shot well in the 3035-3050 fps range. I know several other shooters that have found this same range to be pretty accurate. So, I loaded 12 rounds (2 per charge) from -.5gr to +.5gr and shot them thru a Labradar. Sure enough, the flat spot was right on the load I've used for 2 years. I also agree with Scott's theory that a tight spread is more important at distance than tiny little groups at 100 yards.

 

[black5.3]

Interesting way of doing it. I watched the video and definitely want to try it with my 30-06.

 

[the_accuser]

I tried it recently and was impressed. Once I found the node I was able to get consistent results with that load. Getting ready to use that method again with a new bullet I want to try out.

 

[craigos]

Ditto - has saved me so much time and energy and costs doing it the Saterlee way.

 

[Deleted member 10043]

A hybrid method of least squares. Lol..

seriously though, I would be interested in the working papers for the resizing die primer remover experiments.

 

[ballison]

A hybrid method of least squares. Lol..

seriously though, I would be interested in the working papers for the resizing die primer remover experiments.

Me too! If they tested it, then there may be some validity to it. But I'm having a hard time understanding why decapping and resizing in the same step would affect runout. Maybe someone else can shed some light.

 

[_Raining]

I have never seen a repeatable flat spot in my loads in velocity. Wouldn't you need the ES of each powder charge to be less than the difference between one powder charge and the next to be able to statistically say that there is a spot flatter than the rest? Even with an ES of 5, how do you know that the "flat spots" are not just 3 consecutive rounds where the first round landed on its highest velocity of the ES, the middle one fell on the actual avg, and the third landed on the lowest velocity of the ES. I guess I am just not a good enough reloader to see the benefit of this test.

 

[1MoreAR]

I just did this test with my 6.5 Creedmoor 21" barrel, H4350 started at 41.7-43.3, but I did 2 rounds per each load. I found the velocity didn't change much between 42.5, 42.7 and 42.9, they were right at 2795-2804 fps.

 

[Marksman10x]

This method did not work for me. The load it predicted had terrible accuracy and very high ES/SD. It also failed to show the actual node that was clearly revealed through traditional testing.

However, I do think there is merit to this concept, but one shot per charge weight is insufficient. Three shots per charge weight would give a much more accurate representation.

 

[Deleted member 10043]

Okay, then you need to do the same thing for at least thirty sessions to get a 90% confidence level. A population and sample of one does not mean anything. It just would be nice to see the data backing up OCW and related methods like this.

 

[Marksman10x]

Here are the results from the 10 shot chrono test.

I tried 37.3 and in addition to having too much pressure which was very evident through a sticky bolt and ejector marks on the brass, the chronograph numbers were very high and accuracy was terrible, despite adjusting seating depth. So I went to the next smallest number, 7, which is represented by 36.3 grains.

As you can see twice on this target, 36.2 and 36.3 had SD's of 18 and poor accuracy.

IMO, the center of the node is 36.5 grains. But this was masked by a 25 ft/sec difference on the 10 shot test.

Even combining the two outside groups (36.4 and 36.6) give a SD OF 5.3 and an extreme spread of 15 ft/sec. Further, their poi's are nearly identical (ocw method).

If one were to only consider the first shot velocity of each charge weight on the blue target, and choose the weight with the smallest difference, 36.6 to 36.8 would be the choice. But, that takes the node to it's outer edge, not, IMO optimal and illustrates why one shot per weight does not give an accurate representation. YMMV

 

[_Raining]

You pretty much need an insane SD (1 to 2) for every single charge weight to give this test even a chance at finding the node and even then I am skeptical. We can make charts to figure out MV with respect to ammo temp and we want to plug that data in and get a vertical dope and pull the trigger. The slope of that MV to temperature chart isn't as important as how repeatable it is. This is why people do OCW, when the temperature of your enironment changes we want to only adjust for MV variation, NOT your zero POI shift on top of that... this is what OCW attempts to find, flat spot in POI. But then again I am new to reloading. What I can say is that I am fairly confident in my concept of statistics so I'll continue to shoot 10 shot groups multiple times to determine if something I see is a true pattern or a coincidence.

 

[Barelstroker]

I think it's great to see guys thinking about this sort of stuff instead of just jumping on the bandwagon.
Initially, I wasn't sure what the Satterlee method entailed so, I read up about it. When I got to the part that stated that there was only one sample shot per charge weight, I just sat there kinda stunned. I had to read it again to make sure I had it right. I've no idea what Satterlee was thinking but, I can say he didn't understand the basics of statistical data analysis.
It never ceases to amaze me how guys can just agree with something because some guy they respect says so.

 

[Dthomas3523]

I think it's great to see guys thinking about this sort of stuff instead of just jumping on the bandwagon.
Initially, I wasn't sure what the Satterlee method entailed so, I read up about it. When I got to the part that stated that there was only one sample shot per charge weight, I just sat there kinda stunned. I had to read it again to make sure I had it right. I've no idea what Satterlee was thinking but, I can say he didn't understand the basics of statistical data analysis.
It never ceases to amaze me how guys can just agree with something because some guy they respect says so.

That was never really the actual saterlee method. Everyone focused on a single thing he would do to give him an idea of what’s going on.

And he does things a bit differently now as like everyone he learns more as he goes.

The single shot test was taken completely out of context by the internet and like the game of telephone, twisted.

The one good thing is that a lot of people in practical/tactical shooting use the misinterpreted ladder test as their load development. And they don’t have much problem, leading even more evidence for mine and many other’s opinions that in depth load development is not needed for the game we play.

 

[Barelstroker]

That was never really the actual saterlee method. Everyone focused on a single thing he would do to give him an idea of what’s going on.

And he does things a bit differently now as like everyone he learns more as he goes.

The single shot test was taken completely out of context by the internet and like the game of telephone, twisted.

The one good thing is that a lot of people in practical/tactical shooting use the misinterpreted ladder test as their load development. And they don’t have much problem, leading even more evidence for mine and many others opinions that in depth load development is not needed for the game we play.

There are so many who say it works but, it really can't be because of the numbers that they think are relevant.
I've noticed in my own testing that when a particular powder is well suited, it seems to do well over a wide spectrum &, since many of the PRS shooters already know from experience what works, I think it's more of the case that it would've worked well without any ladder test, just go straight to seating depth testing.
If you're referring to the 10 shot, 10 charge weight scenario, it really is the test we would use to test the correlation of a set of random samples to charge weight vs velocity & nothing more. The Satterlee test is particularly erroneous the smaller the charge weight increments because of overlapping velocities.
I wish we could employ the Satterlee method but, sample numbers & confidence intervals just don't lie.
Basically, if Satterlee is correct then, the rest of statistical analysis is wrong &, that just ain't the case.

 

[Dthomas3523]

There are so many who say it works but, it really can't be because of the numbers that they think are relevant.
I've noticed in my own testing that when a particular powder is well suited, it seems to do well over a wide spectrum &, since many of the PRS shooters already know from experience what works, I think it's more of the case that it would've worked well without any ladder test, just go straight to seating depth testing.
If you're referring to the 10 shot, 10 charge weight scenario, it really is the test we would use to test the correlation of a set of random samples to charge weight vs velocity & nothing more. The Satterlee test is particularly erroneous the smaller the charge weight increments because of overlapping velocities.
I wish we could employ the Satterlee method but, sample numbers & confidence intervals just don't lie.
Basically, if Satterlee is correct then, the rest of statistical analysis is wrong &, that just ain't the case.

Again, you’re taking saterlee out of context. That was never his “method,” just something that he mentioned as part of many things he does.

Also, with most of the 6.5 and 6mm cartridges we use for PRS, you can literally pick most any random charge weight, and as long as your brass prep and powder drop is consistent, it will shoot plenty fine for PRS.

One would have to try to have a higher ES than 40 or so with these cartridges. And you can tighten groups with seating depth.

That’s why people misinterpreting the satterlee method have success. Because modern components are good enough that you won’t miss a practical size target.

Here’s an example of powder charge weights on a 6mm I did. You could literally pick anyone one of them, tune your seating depth, and win a match.

So, if I did what people call the saterlee method, I’d basically just be randomly picking. And I can never pick wrong.

 

[Barelstroker]

Again, you’re taking saterlee out of context. That was never his “method,” just something that he mentioned as part of many things he does.

Also, with most of the 6.5 and 6mm cartridges we use for PRS, you can literally pick most any random charge weight, and as long as your brass prep and powder drop is consistent, it will shoot plenty fine for PRS.

One would have to try to have a higher ES than 40 or so with these cartridges. And you can tighten groups with seating depth.

That’s why people misinterpreting the satterlee method have success. Because modern components are good enough that you won’t miss a practical size target.

Here’s an example of powder charge weights on a 6mm I did. You could literally pick anyone one of them, tune your seating depth, and win a match.

So, if I did what people call the saterlee method, I’d basically just be randomly picking. And I can never pick wrong.

View attachment 7484286

Yes, you've stated my point for why it appears to work.
Out of interest, what was Satterlees idea if not the 10 shot, 10 weight system?
I've no problem believing what you said about guys taking the wrong idea & running with that.
Regards........Barelstroker

 

[Dthomas3523]

Yes, you've stated my point for why it appears to work.
Out of interest, what was Satterlees idea if not the 10 shot, 10 weight system?
I've no problem believing what you said about guys taking the wrong idea & running with that.
Regards........Barelstroker

Very similar to Erik Cortina’s method.

Satterlee tests jump first, then uses chrono for powder. Cortina does powder first and then does jump.

You could say it’s similar to OCW, but doesn’t use too much POI or groups to pick a charge weight.
Chrono for charge weight and groups for jump/seating depth.

And he does more than one round per. I can’t remember how many. Probably 3 or 5. As long as brass prep and charge weights are closely monitored, 5 will at least tell you enough to move forward. I use 5 shots, then once it’s all done, I’ll run 20 shot strings to make sure the numbers remain stable. I’ve never had a 20 string show me that my 5 string wasn’t good enough. But I do a lot of QC checks on my brass.

 

[Barelstroker]

Very similar to Erik Cortina’s method.

Satterlee tests jump first, then uses chrono for powder. Cortina does powder first and then does jump.

You could say it’s similar to OCW, but doesn’t use too much POI or groups to pick a charge weight.
Chrono for charge weight and groups for jump/seating depth.

And he does more than one round per. I can’t remember how many. Probably 3 or 5. As long as brass prep and charge weights are closely monitored, 5 will at least tell you enough to move forward. I use 5 shots, then once it’s all done, I’ll run 20 shot strings to make sure the numbers remain stable. I’ve never had a 20 string show me that my 5 string wasn’t good enough. But I do a lot of QC checks on my brass.

Thankyou.
That sounds like it may be a more logical way to go about it. Considering the load data in your previous post, testing seating depth 1st may well get to an acceptable group &, possibly forego the powder test, perhaps.
That sounds much more reasonable &, even if he's using 3 shot groups, it's still somewhat statistically valid.
Thanks again, you've cleared that up nicely.
Regards..........Barelstroker.

 

[Deleted member 113831]

@Barelstroker
If you want some real entertainment, go to one of the Fudd sites like longrangehunting, and watch fuckers trying to do the "Saterlee" method with light barreled hunting rifles in 300win or some other such caliber.

No amount of logic will convince them that they are pissing into the wind.

 

[Barelstroker]

@Barelstroker
If you want some real entertainment, go to one of the Fudd sites like longrangehunting, and watch fuckers trying to do the "Saterlee" method with light barreled hunting rifles in 300win or some other such caliber.

No amount of logic will convince them that they are pissing into the wind.

Yeah, I can see how if you had a rifle with plenty of previous data & very low SD's were the norm, the 10 shot, 10 charge weight method COULD be expected to give a guide at least. Beyond those two necessities, it's pretty much pissing into the wind.
There are plenty of guys convincing themselves with that method as you've stated. I just can't understand why they believe one shot samples count in the real world when everyone else has had to rely on 5. These guys don't realize that, with only one shot per charge weight, you cannot measure by definition. It's like trying to measure the distance to a mark but, you don't have a starting point from which to measure to that mark. It's just sitting there in space & time with no reference point or direction of travel.
It appears that Satterlee was referencing previous data which had a low enough deviation that it would track with some validity. This does move the goal posts somewhat from standard Statistical analysis however, if circumstances changed at all from the mean of the previous data points, everything goes to shit but, you'd not know it. The 10 shot, 10 weight method is definitely flying blind so, in the final analysis, would it be wise to rely on it, on a regular basis?
Regards.......Barelstroker.

 

[Dthomas3523]

Yeah, I can see how if you had a rifle with plenty of previous data & very low SD's were the norm, the 10 shot, 10 charge weight method COULD be expected to give a guide at least. Beyond those two necessities, it's pretty much pissing into the wind.
There are plenty of guys convincing themselves with that method as you've stated. I just can't understand why they believe one shot samples count in the real world when everyone else has had to rely on 5. These guys don't realize that, with only one shot per charge weight, you cannot measure by definition. It's like trying to measure the distance to a mark but, you don't have a starting point from which to measure to that mark. It's just sitting there in space & time with no reference point or direction of travel.
It appears that Satterlee was referencing previous data which had a low enough deviation that it would track with some validity. This does move the goal posts somewhat from standard Statistical analysis however, if circumstances changed at all from the mean of the previous data points, everything goes to shit but, you'd not know it. The 10 shot, 10 weight method is definitely flying blind so, in the final analysis, would it be wise to rely on it, on a regular basis?
Regards.......Barelstroker.

You can rely on it when shooting targets that aren’t tiny (prs and such is 2moa or so average) and using easy to load cartridges.

For example, say I want to run my BR or dasher at 2775 as I want to see the recoil and trace spotting difference. I’d run a small ladder with single shots to see what charge weight gets me closest.

Then since I’m shooting a cartridge that is virtually impossible (with good brass prep and powder drop) to have an ES (even with temp change) to even come close to missing the targets we shoot, I can just go load that charge and either adjust seating depth or my tuner.

I’ve done this several times with dasher. Pick a velocity I want, find it with single shot ladder, then load it. I’ve then run 20 shot strings strings and it’s always around 10sd and no more than 40es.

So, I would say a single shot ladder is valuable for cartridges like most any 6mm we shoot for prs.

But it is definitely not very valuable for any type of actual load development.

 

[Barelstroker]

You can rely on it when shooting targets that aren’t tiny (prs and such is 2moa or so average) and using easy to load cartridges.

For example, say I want to run my BR or dasher at 2775 as I want to see the recoil and trace spotting difference. I’d run a small ladder with single shots to see what charge weight gets me closest.

Then since I’m shooting a cartridge that is virtually impossible (with good brass prep and powder drop) to have an ES (even with temp change) to even come close to missing the targets we shoot, I can just go load that charge and either adjust seating depth or my tuner.

I’ve done this several times with dasher. Pick a velocity I want, find it with single shot ladder, then load it. I’ve then run 20 shot strings strings and it’s always around 10sd and no more than 40es.

So, I would say a single shot ladder is valuable for cartridges like most any 6mm we shoot for prs.

But it is definitely not very valuable for any type of actual load development.

Thanks again for the explanation & rational insight into this method.
Makes good sense to me.
Regards........barelstroker

 

[Th3un4givin]

I used this method as well. It’s works extremely well. I did an extended version of because I did 20 rounds, 2 of each load just to get a little extra data. I have no doubts it would work with just 10 rounds. The attached pic is the result of the ladder method. Low ES/SD and constantly .3moa, I can’t ask for more than that.

 

[Dthomas3523]

I used this method as well. It’s works extremely well. I did an extended version of because I did 20 rounds, 2 of each load just to get a little extra data. I have no doubts it would work with just 10 rounds. The attached pic is the result of the ladder method. Low ES/SD and constantly .3moa, I can’t ask for more than that.

View attachment 7485485View attachment 7485486View attachment 7485493

It worked because you could have picked any charge weight and had the same results with that cartridge.

 

[Th3un4givin]

It worked because you could have picked any charge weight and had the same results with that cartridge.

Any charge weight is probably a stretch but yes, it’s a pretty forgiving combo.

 

[supercorndogs]

Again, you’re taking saterlee out of context. That was never his “method,” just something that he mentioned as part of many things he does.

Also, with most of the 6.5 and 6mm cartridges we use for PRS, you can literally pick most any random charge weight, and as long as your brass prep and powder drop is consistent, it will shoot plenty fine for PRS.

One would have to try to have a higher ES than 40 or so with these cartridges. And you can tighten groups with seating depth.

That’s why people misinterpreting the satterlee method have success. Because modern components are good enough that you won’t miss a practical size target.

Here’s an example of powder charge weights on a 6mm I did. You could literally pick anyone one of them, tune your seating depth, and win a match.

So, if I did what people call the saterlee method, I’d basically just be randomly picking. And I can never pick wrong.

View attachment 7484286

That is awesome. It supports what @Culpeper has been saying for a long time. Pick a velocity and tune the group size with length.

 

[Deleted member 10043]

Staying within context, keep in mind my goal is to slightly torture the barrel with 10 shots, cold to hot, under five minutes at most, with accuracy under 1.25 moa or better at reasonable distance using middle of the road equipment. Don't confuse my methodology with small groups during development. I'll still get sub moa but not benchrest area. My distances are MR to LR but not ELR. ELR is like giant wave surfing where the surfer needs assistance just getting on the wave. He can't paddle fast enough to do it himself. ELR load development and shooting is a completely different animal. Most people are not into ELR like most surfers are not into mega giant waves. Benchrest goes against what we do like by using flat based low BC bullets for tiny groups at short distance. Again, a horse of a different color and different load development. The best real world comparison for Sarterlee is how the Germans and Russians approached accuracy at Stalingrad with what they had. The Germans used up a lot of resources for a little better accuracy and it still wasn't enough. Think AI vs Remage. Nightforce vs Weaver.

 

[Deleted member 10043]

BTW, I've used this method with 22-250, .244 Rem, 25-06, .260 Rem, 6.5x284, .308, and even .300 H&H and they all worked up a load in a day that lasted. So, don't tell me it doesn't work with the 6.5 Creed everybody told you to get. I use bullets that have been out there a long time. A reloader also needs to check where jammed has moved forward due to erosion and move forward accordingly if and when accuracy falls. You don't need to know where the lands start because you're measuring from jammed and a monkey can find that. If your rifle can't do this method than you have a slippery motherfucker that would be better served as putter. The only thing that can mathematically proven is the geometry of the chamber angle, the geometry of the bullet and paired with the best seating depth range. If your rifle or bullet can't do this than it is probably over engineered. So, I can see how somebody might think it can't be this simple. You don't even need to know the math. Just load a batch at different seating depths and pick the best one. I've never had to change powders as well. All you need to know is what burn rate and MV range works before you start. Any published reloading data will tell you that. Example, they don't call it 4350 for nothing so don't be embarrassed at the counter because the jug says Accurate and not IMR or Hogdon or your using VVN160 instead of H4831 because you looked at a reliable burn rate chart. I never understood people sitting at home with their dick in their hand because they can't get Varget. Lol. Fucking learn to adapt, man. Wasting valuable time and resources because some gay couple, who are now separated, came up with some withcraft is ludicrous.