Load development: is the 10 round ladder test still applicable?

[Freediver111]

I was listening to a podcast the other day and they were talking about how if you try and repeat the results of a 10 round ladder test, you’ll likely get different results (different nodes) each time. Basically calling it a shot in the dark for actually finding a repeatable node.
Can’t recall which podcast, but now I’m curious. I used the 10 round ladder test not too long ago and seemed to work great. Found a load quickly and it’s been extremely accurate and repeatable.
Just got a 300wsm back from the smith and it’s time to find a load, so this had me wondering if many of you are still using this method to find a load, or is it no longer the fad thing to do?

 

[Newbie2020]

Depends on your intended purpose.

I am under the impression that finding the node isn’t so much for accuracy (provided you run a seating test or barrel tuner to account for barrel harmonics) but to avoid excessive pressures. Especially in the old days when powder measurement wasn’t consistent and powders weren’t as temperature stable.

There will be a robust volume of dissenting views.

 

[Dthomas3523]

It was never dependable. The only use was/is to know the roundabout velocity a certain charge weight will be at.

Everything was a product of misunderstanding or misuse of the ladder.

 

[Freediver111]

It was never dependable. The only use was/is to know the roundabout velocity a certain charge weight will be at.

Everything was a product of misunderstanding or misuse of the ladder.

Ok, sounds about what I’ve been hearing. So, I’m working with a 300 wsm. Have 200 and 212 eld x bullets, H4831sc, Norma and Nosler brass, and CCI 250’s. Going to start with 64 grains and work up to 66.5 or so. Barrel is a 1-9.5 twist and going to start at .04” jump. Would it be fair to just load 4 rounds of each charge moving up .5 grains and find the best ES/SD and group size then!? From what I’ve been seeing online, seems like the 2800-2850 velocity range is often where folks are finding the best accuracy. I had a box of Hornady precision hunters with 200 gr eldx and used it for a quick test. Those were actually really good for factory. ES was 25 and SD 15, but groups were .75” and had no problem getting first rounds hits from 500-800. I’m sure my handloads work improve upon those results.

 

[Hawk in WY]

It was never dependable. The only use was/is to know the roundabout velocity a certain charge weight will be at.

Everything was a product of misunderstanding or misuse of the ladder.

Just to put this into perspective. Here is the perfect ladder:

41.7 2830
42.0 2840
42.3 2850
42.5 2850
42.7 2870
43.0 Pressure

Done, right?

The problem is with a true velocity standard deviation of 10, 95% of the time the true mean velocity will be within +/- 20 based on your samples of one. So the 2850 is a random occurrence in a range of 2830 to 2870. Run it again, and you will get different velocities.

 

[Hawk in WY]

I usually take the two or three consecutive loads of five rounds with close to the same point of impact on the target as signaling stable barrel harmonics.

I then run the center of that range with varying COAL and usually find a stable load.

With lead core bullets, I have found 0.20 off the lands is a better starting point.

Good luck.

 

[Buzzinga]

It was never dependable. The only use was/is to know the roundabout velocity a certain charge weight will be at.

Everything was a product of misunderstanding or misuse of the ladder.

Hello Sir,

Are you referring to ladder tests shot on paper at distance to show relative POI? or 10 shot tests using chronographs? or both? I've always considered a ladder test as one that is shot at a target at distance to show relative POI and velocity isn't measured. I was wondering if you could expand on your statement a little, especially the part about it being a product of misunderstanding?

Thank You

 

[Dthomas3523]

Hello Sir,

Are you referring to ladder tests shot on paper at distance to show relative POI? or 10 shot tests using chronographs? or both? I've always considered a ladder test as one that is shot at a target at distance to show relative POI and velocity isn't measured. I was wondering if you could expand on your statement a little, especially the part about it being a product of misunderstanding?

Thank You

Most are referring to the “saterlee” method when talking about these things. Which is completely misinterpreted.

Also, I don’t use anything except a chronograph for powder. Zero reason with modern tools to start shooting stuff at distance and deciphering holes on paper.

That was great when we didn’t have modern chrono graphs, modern brass, weighing charges to the kernel, etc. Like most all things from the 90’s and prior, we have evolved.

 

[Dthomas3523]

Just to put this into perspective. Here is the perfect ladder:

41.7 2830
42.0 2840
42.3 2850
42.5 2850
42.7 2870
43.0 Pressure

Done, right?

The problem is with a true velocity standard deviation of 10, 95% of the time the true mean velocity will be within +/- 20 based on your samples of one. So the 2850 is a random occurrence in a range of 2830 to 2870. Run it again, and you will get different velocities.

It gets you in the ballpark of your normal ES.

If all my loads always have a 30es or so, I know about where each charge weight will be once I run it over the chrono.

So if my goal is 2850 and I see some charges in that area, I know where I’m going to focus. That’s all this is good for.

If your loading methods don’t consistently give you 30es or lower, then you are correct.....completely useless.

 

[Deleted member 113831]

Would it be fair to just load 4 rounds of each charge moving up .5 grains and find the best ES/SD and group size then!? From what I’ve been seeing online, seems like the 2800-2850 velocity range is often where folks are finding the best accuracy.

When working up to find pressure, I use three rounds of each charge in 1% increments and am from .030 to .040 off the lands.

I do take note of SD in each charge weight. Although it is a bullshit number with only 3 rounds per charge, if you do happen to see a trend of 2 or 3 charges in a row with noticeably smaller SD's then it might have some significance.

 

[TX_Diver]

It gets you in the ballpark of your normal ES.

If all my loads always have a 30es or so, I know about where each charge weight will be once I run it over the chrono.

So if my goal is 2850 and I see some charges in that area, I know where I’m going to focus. That’s all this is good for.

If your loading methods don’t consistently give you 30es or lower, then you are correct.....completely useless.

Is there a validity to it if you shoot 3 shot groups over a chrono?

I don't see much purpose to a sample size of 1, but am kinda already on my way to testing this for myself. Yesterday I loaded up 19.5gr to 22.1gr of N140 under a 77gr SMK yesterday @ .2gr increments. 6 rounds of each to shoot 3 over a magneto speed, and 3 at paper (OCW test) and see what the results of each showed and if they lined up or not.

 

[Dthomas3523]

Is there a validity to it if you shoot 3 shot groups over a chrono?

I don't see much purpose to a sample size of 1, but am kinda already on my way to testing this for myself. Yesterday I loaded up 19.5gr to 22.1gr of N140 under a 77gr SMK yesterday @ .2gr increments. 6 rounds of each to shoot 3 over a magneto speed, and 3 at paper (OCW test) and see what the results of each showed and if they lined up or not.

Depends on your loading methods. The better your QC and quality of your loads, the smaller the sample size it takes to give you a good idea what’s going on.

Also, for 99% of shooters, load development is largely a waste of time. Especially if shooting a newer 6 or 6.5 variant.

Pick a speed, load to a kernel, be fairly meticulous in your brass prep, use seating depth to get acceptable groups, and go shoot. It’s pretty easy to load ammo with an ES well inside the target size most people are shooting.

 

[Steel head]

I do it with 2 shots per load normally and a .2 to .3 spread depending on case capacity.
I always just shoot them at steel at distance with a chrony on it to record speeds.

I haven’t done it yet with my V3, my old Hornandy scale was certainly sloppy enough to throw you of if you didn’t throw out anomalies but I was always able to get a nice and forgiving load with that method rather quickly.

 

[Newbie2020]

Depends on your loading methods. The better your QC and quality of your loads, the smaller the sample size it takes to give you a good idea what’s going on.

Also, for 99% of shooters, load development is largely a waste of time. Especially if shooting a newer 6 or 6.5 variant.

Pick a speed, load to a kernel, be fairly meticulous in your brass prep, use seating depth to get acceptable groups, and go shoot. It’s pretty easy to load ammo with an ES well inside the target size most people are shooting.

I’m beyond my depth at this point but This seems to align w my minuscule understanding of physics. I’ve never understood why or how a given load could be more or less “accurate” without regard for how the difference in pressure/velocity simultaneously affected barrel harmonics, for which we account by a seating depth test or a barrel tuner.

 

[Dthomas3523]

I’m beyond my depth at this point but This seems to align w my minuscule understanding of physics. I’ve never understood why or how a given load could be more or less “accurate” without regard for how the difference in pressure/velocity simultaneously affected barrel harmonics, for which we account by a seating depth test or a barrel tuner.

The answer would be in the velocity ES. Which is dependent on the target size + distance.

I can’t tell you why certain charge weights perform better. I’d assume it’s something to do with case capacity/fill and other such things.

Also, if people would run 50+ rounds over a chrono of each charge weight, they’d see those numbers are *much* closer together (ES and such) than they realize. Making it even more trivial vs their intended target size.

Things like F class and ELR it matters much more. Practical shooting? Not so much.

And yea, seating depth will tighten up pretty much any charge weight. Tying groups to charge weight is circa 1995 stuff.

 

[TX_Diver]

Depends on your loading methods. The better your QC and quality of your loads, the smaller the sample size it takes to give you a good idea what’s going on.

Also, for 99% of shooters, load development is largely a waste of time. Especially if shooting a newer 6 or 6.5 variant.

Pick a speed, load to a kernel, be fairly meticulous in your brass prep, use seating depth to get acceptable groups, and go shoot. It’s pretty easy to load ammo with an ES well inside the target size most people

If I had to guess my shooting will be the limiting factor for 99% of scenarios.

.223 is cheap to load though so figured it'd be an interesting test. Home sick today so may shoot the first string later if it warms up (supposed to almost break freezing today!) Rest of the week sucks for weather but will post an update later.

 

[Newbie2020]

@TX_Diver 3 rds over chrono and 3 on paper doesn't seem like enough to test the theory. More likely to tell you something that isn't true than to "put this to bed", so to speak.

Not to help you waste your ammo and components, but something like 10 or 20 rds over chrono and into paper seems more likely to test the outcome @Dthomas3523 has proposed.

 

[TX_Diver]

@TX_Diver 3 rds over chrono and 3 on paper doesn't seem like enough to test the theory. More likely to tell you something that isn't true than to "put this to bed", so to speak.

Not to help you waste your ammo and components, but something like 10 or 20 rds over chrono and into paper seems more likely to test the outcome @Dthomas3523 has proposed.

Ya. The test definitely was just for myself and to see what I prefer for load development more than to definitively prove or disprove a theory. My reloading practices (or lack thereof) will obviously heavily influence the test. I'm a pretty new reloader so I think I'll give it a few years and many more rounds downrange before I pursue proving anything haha. I was also curious to do this test now with some early loads developments and see what happens if I run it again later (i.e. has my loading improved).

All very theoretical with lots of variables but that was part of the point of me getting the .223 to play with.

My main reason for sharing the info is that I'm sure others will be able to give good feedback and maybe validate a portion of my results, or alternatively invalidate what appears to be a result. People do load development with less rounds so hopefully I can gather something remotely useful out of 80 for myself.

 

[Newbie2020]

Given that's your intended use, you could save a bundle of components and skip the powder ladder, shoot a single moderate load recommended in the reloading section for .223Rem for your powder of choice over a chrono, and provided mv is acceptable, do a seating depth test to tighten the group, and you're gtg.

The counter point being proposed is the ES/sd for 3 rds is likely misleading, therefore useless. The suggestion is that if you finish the 3 rd test and do another identical 3 rd ladder test, you'll get a completely new velocity "node" and completely different es/sd.

So the thesis is that we can either:

(a) pick a single middle of the road powder load and tune seating depth for accuracy;
(b) do a larger (10-20 rds per powder charge) load test and learn (possibly) that es/sd is roughly identical across loads, pick a load, and tune seating depth for accuracy; or
(c) do a small load ladder test like we've always done and confidently learn something that possibly is wrong and misleading but actually also won't hurt our load development, but is also a waste of time and components.

 

[308pirate]

I usually take the two or three consecutive loads of five rounds with close to the same point of impact on the target as signaling stable barrel harmonics.

I then run the center of that range with varying COAL and usually find a stable load.

With lead core bullets, I have found 0.20 off the lands is a better starting point.

Good luck.

Yep, you basically described the Optimal Charge Weight method. Muzzle velocity is not a metric during OCW.

 

[TX_Diver]

Given that's your intended use, you could save a bundle of components and skip the powder ladder, shoot a single moderate load recommended in the reloading section for .223Rem for your powder of choice over a chrono, and provided mv is acceptable, do a seating depth test to tighten the group, and you're gtg.

The counter point being proposed is the ES/sd for 3 rds is likely misleading, therefore useless. The suggestion is that if you finish the 3 rd test and do another identical 3 rd ladder test, you'll get a completely new velocity "node" and completely different es/sd.

So the thesis is that we can either:

(a) pick a single middle of the road powder load and tune seating depth for accuracy;
(b) do a larger (10-20 rds per powder charge) load test and learn (possibly) that es/sd is roughly identical across loads, pick a load, and tune seating depth for accuracy; or
(c) do a small load ladder test like we've always done and confidently learn something that possibly is wrong and misleading but actually also won't hurt our load development, but is also a waste of time and components.

That makes sense. I was also wondering along the lines of what you listed in (a), is if I could take a powder charge essentially at random and adjust seating depth to make it shoot by adjusting seating depth.

Right now I'm about 1/8" over mag length (1.953 CBTO, 2.341 COAL)

Using Erik Cortina's method of finding the lands I got all kinds of results by seating the bullet by closing the bolt and re-opening it (most in the CBTO range of 1.97 but some at 1.99) At current length I'm about .002" back from where I could close the bolt w/ a sharpie coated bullet, and re-open it without finding marks from the rifling on it. Completely unscientific but it gave me a warm fuzzy feeling that I wasn't sticking the bullet into the rifling at least.

When I do my seating test maybe I'll do it for the chosen charge weight and also an arbitrary middle of the road weight too in the interest of testing your first thesis.

Again all this in the context of curiosity/learning for myself more than trying to prove/disprove something.

 

[kthomas]

The ladder test, AKA the "Satterlee" method is a bunch of garbage.

When I started into reloading, I bought into it. Why not? It sounds really easy (only 10 rounds!), and it was backed by a bunch of top level PRS shooters. So that's what I did for years. My results were decent, but I was also using high quality components and reloading gear - Lapua brass, Berger bullets, autotrickler w/FX-120i, etc.

At one point I decided to load up two identical charge weight ladders, to shoot back to back. Being an engineer, more data is better, and I wanted to corroborate the data from the first ladder. I did this for a while, and found out that any so-called "node" you would find in one load, was pretty much never repeatable in a second, identical ladder. The "node" didn't exist. The data from 10 shots (one of each charge weight), is statistically insignificant, it means nothing. Good thing my university statistics teacher didn't find out I was shooting 10 shot ladders, he would've failed my ass.

I don't use ladders now for anything other then finding approximate velocity per charge weight, and pressure. My loads now have much better ES/SD then they did when using the "Satterlee" method, because those so-called "nodes" that I found never existed in the first place. The good news, is that with good quality reloading components and equipment, it's hard to reload bad rounds these days. But if you want to optimize your reloads, you won't be doing it with the "Satterlee" method.

 

[TX_Diver]

The ladder test, AKA the "Satterlee" method is a bunch of garbage.

When I started into reloading, I bought into it. Why not? It sounds really easy (only 10 rounds!), and it was backed by a bunch of top level PRS shooters. So that's what I did for years. My results were decent, but I was also using high quality components and reloading gear - Lapua brass, Berger bullets, autotrickler w/FX-120i, etc.

At one point I decided to load up two identical charge weight ladders, to shoot back to back. Being an engineer, more data is better, and I wanted to corroborate the data from the first ladder. I did this for a while, and found out that any so-called "node" you would find in one load, was pretty much never repeatable in a second, identical ladder. The "node" didn't exist. The data from 10 shots (one of each charge weight), is statistically insignificant, it means nothing. Good thing my university statistics teacher didn't find out I was shooting 10 shot ladders, he would've failed my ass.

I don't use ladders now for anything other then finding approximate velocity per charge weight, and pressure. My loads now have much better ES/SD then they did when using the "Satterlee" method, because those so-called "nodes" that I found never existed in the first place. The good news, is that with good quality reloading components and equipment, it's hard to reload bad rounds these days. But if you want to optimize your reloads, you won't be doing it with the "Satterlee" method.

What have you gone to now for load development and determining a charge weight/seating depth?

 

[kthomas]

What have you gone to now for load development and determining a charge weight/seating depth?

I use bullet seating depth tests for precision, I use Berger Hybrids which are pretty forgiving. I haven't tried long jumps, but I find 10 to 20 thou off the lands always shoots really great. I never chase the lands, I seat bullets at the same OAL and they continue to shoot great in my chamber.

For my cartridges, through experience I've generally found speeds that cartridges like. For 140's in a 24" 6.5 Creedmoor, I've found ~2830 fps to be a great speed. For 6BRA, I've settled on ~2970 fps out of my 28" barrel. I'll load a ladder with different charge weights, and find what the approximate velocity is per charge. From there, I will load up a few 5 round test groups, slightly above and below my desired velocity (say ~2970 fps for 6BRA). I'll run the 5 round groups over a chrono, to test for ES/SD. I'll then pick what has the lowest ES/SD, though I generally find that they are all usually very similar (~4-5 SD).

 

[TX_Diver]

I use bullet seating depth tests for precision, I use Berger Hybrids which are pretty forgiving. I haven't tried long jumps, but I find 10 to 20 thou off the lands always shoots really great. I never chase the lands, I seat bullets at the same OAL and they continue to shoot great in my chamber.

For my cartridges, through experience I've generally found speeds that cartridges like. For 140's in a 24" 6.5 Creedmoor, I've found ~2830 fps to be a great speed. For 6BRA, I've settled on ~2970 fps out of my 28" barrel. I'll load a ladder with different charge weights, and find what the approximate velocity is per charge. From there, I will load up a few 5 round test groups, slightly above and below my desired velocity (say ~2970 fps for 6BRA). I'll run the 5 round groups over a chrono, to test for ES/SD. I'll then pick what has the lowest ES/SD, though I generally find that they are all usually very similar (~4-5 SD).

So essentially you're picking a target velocity and doing some minor testing around it then playing with seating depth to shrink groups?

 

[spife7980]

So essentially you're picking a target velocity and doing some minor testing around it then playing with seating depth to shrink groups?

After you have done enough to know what works, yeah. In things, like a dasher with lapua brass and somewhere between 31-32 grains varget and a 105-115 gr bullet .015-.035 off the lands, it will be where you like it no matter what so you can cut to it.
Go down the line and they will all be right about that. In this situation where he knows 3 barrels worth of dashers like the same thing one can skip to the front of the line and get right to it in only a handful of shots once the barrels sped up.

Go to something thats not so well vetted and you will need to expand your horizons a bit.

 

[kthomas]

After you have done enough to know what works, yeah. In things, like a dasher with lapua brass and somewhere between 31-32 grains varget and a 105-115 gr bullet, it will be where you like it no matter what so you can cut to it.
Go down the line and they will all be right about that. In this situation where he knows 3 barrels worth of dashers like the same thing one can skip to the front of the line and get right to it in only a handful of shots once the barrels sped up.

Go to something thats not so well vetted and you will need to expand your horizons a bit.

Exactly.

If you don't have a target velocity in mind from previous experience, you can look at the recipe threads here for cartridges, and for the BR type cartridges, accurateshooter.com is another good resource. Don't be afraid to play around, but like anything, it takes a bit of time and experience to find what works "best".

What I think is more important then what specific method you use, is applying your method consistently, and utilizing quality components (like Lapua and Berger) and quality reloading equipment. If you have these things, it makes reloading relatively easy.

 

[TX_Diver]

Exactly.

If you don't have a target velocity in mind from previous experience, you can look at the recipe threads here for cartridges, and for the BR type cartridges, accurateshooter.com is another good resource. Don't be afraid to play around, but like anything, it takes a bit of time and experience to find what works "best".

What I think is more important then what specific method you use, is applying your method consistently, and utilizing quality components (like Lapua and Berger) and quality reloading equipment. If you have these things, it makes reloading relatively easy.

Makes sense. I don't have a target velocity in mind but intentionally started with the .223 to keep the cost lower as I experiment. I've reloaded a bit in the past but it was try different charge weights and pick the smallest groups when I did that with my 30-06. Now that I came back to it years later that doesn't seem to be the way anymore so working on reading up and building up my experience a bit more.