Just for discussion - 300 WSM Data

[Shorthunter]

I find it interesting to compare book data sometimes. I work up loads for a specific rifle when I can, but I do produce reloads for general use (multiple guns). Sometimes the book data is halfway close with the max charge being 3 or 6% +/- and then there's data like this where it takes quite a bit of time to decipher.

Hogdon, Lee and Hornady snips below. Just look at the numbers for Winchester 760. There is a significant discrepancy between all 3 sources.

This isn't bad information though. When I look at it I see potential nodes at 63.1, 65.0 and 69.0. What do you guys see? Any thoughts other than the recommendation to start at the lowest and work up (not saying it's not good advice, it just gets overstated sometimes)

 

[A382DWDZQ]

I think the start low and work up is a good safety measure. I think there is flexibility in what the work up looks like after the start low, depending on what those first shots look like.

 

[Harvey_NW]

To me, that's kind of a loose comparison, so I would expect there to be some variance. The first one is very specific, the second is a different bullet construction, and the 3rd encompasses a variety of different bullets. I've found that if you compare data with relative component and test barrel specs, you get a lot more consistent results. And I don't believe in nodes, but that's been beat to death.

 

[MThuntr]

To me, that's kind of a loose comparison, so I would expect there to be some variance. The first one is very specific, the second is a different bullet construction, and the 3rd encompasses a variety of different bullets. I've found that if you compare data with relative component and test barrel specs, you get a lot more consistent results. And I don't believe in nodes, but that's been beat to death.

I agree. Partition vs possibly a copper bullet vs data for a bunch. Too many variables for a consistent read.

To the OP even though he said don't say it: Start low, working up until you achieve desired results. Perceived nodes aren't going to be interpreted from printed load data that'll come from your rifle data. You're potentially playing with fire by randomly picking loads.

EDIT: Not knowing the bullet of choice, I'd probably start at 60gr and work up in .5gr increments if I was doing a ladder test in search of a max. Possibly a lower increment if I wanted a more refined data set. Ideally, it will be obvious where things are consistent and you work from there.

 

[wind gypsy]

on the lee page - notice how H4350 has 62.0 for the copper and 65.5 for the lead jacketed 165? Fair to assume that 62.5 for the W760 would then also be 65.5+

But yeah, i've found a lot of published load data that sucks for the barrels/components most people use. Which all points to understanding what impacts pressure and velocity and reading signs being more important than what published data says.

 

[Shorthunter]

I agree. Partition vs possibly a copper bullet vs data for a bunch. Too many variables for a consistent read.

To the OP even though he said don't say it: Start low, working up until you achieve desired results. Perceived nodes aren't going to be interpreted from printed load data that'll come from your rifle data. You're potentially playing with fire by randomly picking loads.

EDIT: Not knowing the bullet of choice, I'd probably start at 60gr and work up in .5gr increments if I was doing a ladder test in search of a max. Possibly a lower increment if I wanted a more refined data set. Ideally, it will be obvious where things are consistent and you work from there.

I agree but I will start a bit higher and work in .2 increments for the specific load I am working on. I definitely wouldn't advocate the idea of picking a random load but there is a lot to be gathered from the published max.

As a general reply to all and for further discussion - Many of the manufacturers will publish their last charge weight before the load came apart (accuracy wise) as their max. If one data source is 3% or 6% off from another source, I can assume with some degree of certainty that those were the last areas where they found accuracy (in their particular test environment).

There are nodes for every cartridge where velocity will flatten and they occur at 3% intervals regardless of what rifle the round is coming out of. If you fire the 165gr Sierra BT SP from 10 different 300 WSM rifles using Winchester brass, Winchester primers and Hogdon Superperformance powder, there will be an area in each ladder test that points to 1 charge weight working in every gun. Is that to say a hotter charge won't work a little better in a couple of the guns, absolutely not.

People with experience in reloading know that every barrel is just a bit different. Maybe one likes .005" more jump (with all else staying the same) than another or one likes a specific powder or likes the load a little hotter. Same can be said for the projectiles.

I started this thread as a discussion because I as bored, let's keep it going. Lol

 

[wind gypsy]

I agree but I will start a bit higher and work in .2 increments for the specific load I am working on. I definitely wouldn't advocate the idea of picking a random load but there is a lot to be gathered from the published max.

As a general reply to all and for further discussion - Many of the manufacturers will publish their last charge weight before the load came apart (accuracy wise) as their max. If one data source is 3% or 6% off from another source, I can assume with some degree of certainty that those were the last areas where they found accuracy (in their particular test environment).

There are nodes for every cartridge where velocity will flatten and they occur at 3% intervals regardless of what rifle the round is coming out of. If you fire the 165gr Sierra BT SP from 10 different 300 WSM rifles using Winchester brass, Winchester primers and Hogdon Superperformance powder, there will be an area in each ladder test that points to 1 charge weight working in every gun. Is that to say a hotter charge won't work a little better in a couple of the guns, absolutely not.

People with experience in reloading know that every barrel is just a bit different. Maybe one likes .005" more jump (with all else staying the same) than another or one likes a specific powder or likes the load a little hotter. Same can be said for the projectiles.

I started this thread as a discussion because I as bored, let's keep it going. Lol

My understanding is that load manuals go up until they hit SAAMI max or close in general without regard to accuracy.

Also, i don't believe the velocity flatten node idea has been proven to be real and repeatable with statistically significant sample sizes. If you've got proof to the contrary, please post it.

 

[MThuntr]

There are nodes for every cartridge where velocity will flatten and they occur at 3% intervals regardless of what rifle the round is coming out of

I've never seen this. I reload a lot and it's never been predictable in any statistically significant manner.

 

[Shorthunter]

My understanding is that load manuals go up until they hit SAAMI max or close in general without regard to accuracy.

Also, i don't believe the velocity flatten node idea has been proven to be real and repeatable with statistically significant sample sizes. If you've got proof to the contrary, please post it.

If everyone went up to SAAMI max and stopped, I don't believe we would get various published pressures. Isn't there 1 published SAAMI max for every cartridge?

The Lee book compiles data from several sources and there is quite a range in pressure for each max charge weight.

 

[Harvey_NW]

I agree but I will start a bit higher and work in .2 increments for the specific load I am working on. I definitely wouldn't advocate the idea of picking a random load but there is a lot to be gathered from the published max.

As a general reply to all and for further discussion - Many of the manufacturers will publish their last charge weight before the load came apart (accuracy wise) as their max. If one data source is 3% or 6% off from another source, I can assume with some degree of certainty that those were the last areas where they found accuracy (in their particular test environment).

There are nodes for every cartridge where velocity will flatten and they occur at 3% intervals regardless of what rifle the round is coming out of. If you fire the 165gr Sierra BT SP from 10 different 300 WSM rifles using Winchester brass, Winchester primers and Hogdon Superperformance powder, there will be an area in each ladder test that points to 1 charge weight working in every gun. Is that to say a hotter charge won't work a little better in a couple of the guns, absolutely not.

People with experience in reloading know that every barrel is just a bit different. Maybe one likes .005" more jump (with all else staying the same) than another or one likes a specific powder or likes the load a little hotter. Same can be said for the projectiles.

I started this thread as a discussion because I as bored, let's keep it going. Lol

Highly suggest listening to the podcast and reading the entire thread since you're bored, but if you want a shortcut to a bunch of data and context on the subject start here. https://rokslide.com/forums/threads/your-groups-are-too-small.290821/post-3453229

 

[Shorthunter]

Highly suggest listening to the podcast and reading the entire thread since you're bored, but if you want a shortcut to a bunch of data and context on the subject start here. https://rokslide.com/forums/threads/your-groups-are-too-small.290821/post-3453229

Your link takes me to a video I've watched. I understand his statistical analysis and it is definitely good information.

My original post was in regard to 3 books publishing vastly different max charge weights and how someone might use that information to determine a good starting point.

Why do our sources vary so much, especially when the data is often published with the same brass, same primer and the same weight/ type (jacketed, solid, etc.) of bullet? They even publish pressures that vary over 5,000psi which is close to 10% of the published max. If the published data we are getting states that 70 grains of 780 only produced 59,500psi but SAAMI max is 65,000 why did the manufacturer publish a 'max charge weight' that generated such low pressure10% under max?

 

[Harvey_NW]

Your link takes me to a video I've watched. I understand his statistical analysis and it is definitely good information.

I was referencing his valuable input to the rest of the thread, specifically where he proves his own initial theory of "nodes" and tuning to be no significant improvement to the baseline load of the same components established with that rifle.

My original post was in regard to 3 books publishing vastly different max charge weights and how someone might use that information to determine a good starting point.

Again, you provided a loose example and were given advice on how to navigate that. If you can confirm those 3 data sets were all the most up to date publications using the same length/twist/groove test barrel, brass, primer, etc., I would expect the results to be a lot closer.

Why do our sources vary so much, especially when the data is often published with the same brass, same primer and the same weight/ type (jacketed, solid, etc.) of bullet? They even publish pressures that vary over 5,000psi which is close to 10% of the published max. If the published data we are getting states that 70 grains of 780 only produced 59,500psi but SAAMI max is 65,000 why did the manufacturer publish a 'max charge weight' that generated such low pressure10% under max?

I suggest reading page 8 and 9 on the SAAMI Velocity and Pressure data publication, and maybe you can draw your own conclusion. The way I interpret it, there's more to it than just a max pressure. It outlines factors like maximum average pressure, standard deviation, and maximum extreme variation, that I would assume would be accounted for in publishing load data. So add the variability of different component manufacturers, barrel manufacturers, barrel specs, lot numbers, etc. and you can easily see how there's room for error, especially with older cartridges.

 

[Shorthunter]

I was referencing his valuable input to the rest of the thread, specifically where he proves his own initial theory of "nodes" and tuning to be no significant improvement to the baseline load of the same components established with that rifle.


Again, you provided a loose example and were given advice on how to navigate that. If you can confirm those 3 data sets were all the most up to date publications using the same length/twist/groove test barrel, brass, primer, etc., I would expect the results to be a lot closer.


I suggest reading page 8 and 9 on the SAAMI Velocity and Pressure data publication, and maybe you can draw your own conclusion. The way I interpret it, there's more to it than just a max pressure. It outlines factors like maximum average pressure, standard deviation, and maximum extreme variation, that I would assume would be accounted for in publishing load data. So add the variability of different component manufacturers, barrel manufacturers, barrel specs, lot numbers, etc. and you can easily see how there's room for error, especially with older cartridges.

Thank you for sharing this information and keeping the conversation going. I read about 2 pages into his responses after the video link. He makes some great points but I am not sure all of the controls are good enough to validate all of the data. I don't say that to discredit his work because I really think it is awesome that he put in the time and work, he shared his results and then followed up with it. He's very sharp, I just have a tendency to question all statistical evaluation after a while. With my experience in manufacturing, it often seems that the more you run the tests and the more data you add the less sure you are about the results. And if controls are not 100% spot on, every data point you add convolutes the data set. Of course we used acceptable ranges and predetermined highs/ lows in manufacturing. If we just analyzed the data to a spec we would have destroyed 90% of everything we produced.

In regards to the published book data, a Hogdon tech rep told me their max published max is where their tests gave them good accuracy before signs of pressure. I'd say there is plenty that goes into their decision on what to publish, with expected accuracy being one of the big contributors.

I'll add that I don't believe in nodes because of YouTube videos, I've seen the flat spots in many different tests I've done and tests that others have shared. I've also had to redo my own tests because the initial feedback was inconclusive (more on this in the next paragraph). That being said I'll try to share test results from my 300 WSM rifles, even if it doesn't confirm a node. I'll be shooting ladder tests with 3 different rifles at some point in the near future.

I would say that variation in materials probably makes it hard for us to recognize flat spots (nodes) more often than not. Neck concentricity, consistent neck tension on the bullet, primer weight, bullet weight, etc. If we are shooting groups for accuracy and we have 1 bullet group outside of what we expect, we can contribute that to wind, our shot execution or a few other factors. Sometimes that's the case and sometimes it's the round itself. Based on my experience shooting ladder tests through a chronograph and onto paper, I can tell you that me taking shortcuts in case prep has led to me reshooting the string a few times.

 

[jimh406]

Seems to me the standard advice applies like you suggest. Start at/near the bottom and work your way up.

There usually isn't enough information to know what gun they used which could cause quite a bit of variance.

 

[Shorthunter]

Agreed @jimh406

To add to my comment above, if I refer to nodes I am not referring to the so called accuracy node. I don't believe the gun will shoot more accurately in a flat spot but I do believe it can reduce deviation a bit across different conditions. For me if I find a flat spot where my speed doesn't change much over 3 shots/ 6 tenths that tells me I have a slightly bigger margin of error when it comes to weighing my powder charge and it may give me a bit of leniency for powders that are temperature sensitive. If I find a flat spot in the same vicinity when testing multiple rifles, it tells me that I can sell my manufactured ammunition with confidence (confidence that it will shoot well in every customers gun).

 

[ropeup79]

The thing about the Lee Manual is that the data is gathered from other sources. They do not test the loads themselves.
Also, different bullets of the same weight may have very different characteristics which cause pressures to very with similar powder charges. 65 gr. of X powder might be great with Y bullet but over pressure with Z bullet.

 

[Harvey_NW]

Thank you for sharing this information and keeping the conversation going. I read about 2 pages into his responses after the video link. He makes some great points but I am not sure all of the controls are good enough to validate all of the data. I don't say that to discredit his work because I really think it is awesome that he put in the time and work, he shared his results and then followed up with it. He's very sharp, I just have a tendency to question all statistical evaluation after a while. With my experience in manufacturing, it often seems that the more you run the tests and the more data you add the less sure you are about the results. And if controls are not 100% spot on, every data point you add convolutes the data set. Of course we used acceptable ranges and predetermined highs/ lows in manufacturing. If we just analyzed the data to a spec we would have destroyed 90% of everything we produced.

In regards to the published book data, a Hogdon tech rep told me their max published max is where their tests gave them good accuracy before signs of pressure. I'd say there is plenty that goes into their decision on what to publish, with expected accuracy being one of the big contributors.

I'll add that I don't believe in nodes because of YouTube videos, I've seen the flat spots in many different tests I've done and tests that others have shared. I've also had to redo my own tests because the initial feedback was inconclusive (more on this in the next paragraph). That being said I'll try to share test results from my 300 WSM rifles, even if it doesn't confirm a node. I'll be shooting ladder tests with 3 different rifles at some point in the near future.

I would say that variation in materials probably makes it hard for us to recognize flat spots (nodes) more often than not. Neck concentricity, consistent neck tension on the bullet, primer weight, bullet weight, etc. If we are shooting groups for accuracy and we have 1 bullet group outside of what we expect, we can contribute that to wind, our shot execution or a few other factors. Sometimes that's the case and sometimes it's the round itself. Based on my experience shooting ladder tests through a chronograph and onto paper, I can tell you that me taking shortcuts in case prep has led to me reshooting the string a few times.

Your groups are too small.

 

[wind gypsy]

From Litz's book as posted on a thread on accurateshooter. Highlight is more relevant to that thread, 3rd bullet is relevant to this thread.

 

[A382DWDZQ]

One possible reason book being 10% less than SAAMI max is so that if a batch of powder runs hotter than what they tested with, the load is at max and not 10% over max.

 

[Shorthunter]

From Litz's book as posted on a thread on accurateshooter. Highlight is more relevant to that thread, 3rd bullet is relevant to this thread.

View attachment 662219

I always shoot 2-3 ladders and stack the results. I chronograph each shot and put them on paper while doing so (100 or 200 yards). Once I think I have a couple of forgiving charge weights I'll shoot groups with those charge weights and then read the target (Jack Neary explains in interview with Erik Cortina)

There's a lot of ways to develop loads and there's good in each method.