Myths and Mysticism in Load Development

[PeteFox]

This is another study on tuners, more rigor and a larger sample size… but I suspect it will be dismissed on some grounds by some folk somewhere….

https://www.kineticsecuritysolutions.co ... ng-results

170E2E69-4FD5-4EDE-940C-E1CDCE78844C.pngNo another national championship won using a tuner…

When will these people learn that’s not how it done…

Well done to Cal Waldner!!

The problem I see is that in the first quote you promote the value of more rigour and a larger sample size as a good thing, but choose to ignore exactly that when the findings don't suit.

The framing of the second quote is a schoolboy debating ploy. It belittles the achievement of the shooter.
I don't think anyone here has said that events can't be won if a tuner is used. If the majority of shooters are using these things then might not winning with a tuner come by default? not because of the tuner.

Does anyone here have any evidence that the value of these things doesn't disappear in the 'noise' of a large test?
Is a powder load that sits right in the 'node', still good on a day when the temp/humidity is different? or is powder load v's muzzle velocity simply linear and nodes the consequence of small sample sizes?
Will a large sample size drown out a perceived powder node?

These are the questions that this topic sought to answer. but... a whole lot of energy has been devoted to soothing bruised egos, misunderstandings, manufactured umbrage and deliberate shit stirring.
Meanwhile, we don't have an answer.
Pete

[Drop shot]

This is another study on tuners, more rigor and a larger sample size… but I suspect it will be dismissed on some grounds by some folk somewhere….

https://www.kineticsecuritysolutions.co ... ng-results

170E2E69-4FD5-4EDE-940C-E1CDCE78844C.pngNo another national championship won using a tuner…

When will these people learn that’s not how it done…

Well done to Cal Waldner!!

The problem I see is that in the first quote you promote the value of more rigour and a larger sample size as a good thing, but choose to ignore exactly that when the findings don't suit.

The framing of the second quote is a schoolboy debating ploy. It belittles the achievement of the shooter.
I don't think anyone here has said that events can't be won if a tuner is used. If the majority of shooters are using these things then might not winning with a tuner come by default? not because of the tuner.

Does anyone here have any evidence that the value of these things doesn't disappear in the 'noise' of a large test?
Is a powder load that sits right in the 'node', still good on a day when the temp/humidity is different? or is powder load v's muzzle velocity simply linear and nodes the consequence of small sample sizes?
Will a large sample size drown out a perceived powder node?

These are the questions that this topic sought to answer. but... a whole lot of energy has been devoted to soothing bruised egos, misunderstandings, manufactured umbrage and deliberate shit stirring.
Meanwhile, we don't have an answer.
Pete

It keeps getting pointed out that the smug attitudes are what has been attacked, not the data. You HAVE to be choosing to ignore this fact at this point. Probably because it's your attitude that is contributing to the stink and you don't want to take ownership.

Everything you talk about has been covered and addressed and ignored and the standard throw away is "that's not a statistical" etc etc because that negates any argument or discussion and that's all Bryan has taught you to parrot.

Bryan may be right, he may be wrong, i'm not going to burn at the stake anyone in here's belief either way.

Again.

Here's 7 x 10 shot strings over 5 different days at various points in the barrel life.
There's 2 x 10 shot strings where we plotted the impact convergence
We used a skip test on GRT
Then a confirmation of 5 rounds over the chrono to make sure i'm at the MV I needed/wanted to be.
All tests managed to coalesce at 39.3gr over an entire year until the throat eroded and i had to adjust. That was at 550 rounds. I know this because I check my barrel health with 10 shot tests.

Here's another where I artificially simulated temp variation in the bullets by loading up and down in the node. Again, the SD's are higher because i can't tune for jump as they are AR10 Magazines and I'm limited to Mag length.

I have log data that shows this occurring with temp variation from season to season - i do this for all my guns because i want to know, and so i have checked it.

I'm open to there being variables that affect how this works and that maybe it doesn't, but this has not been my experience, and considering the calibre, experience, and skill and accomplishment of some of the people in here, the smug attitude that they receive for disagreeing with you offends me.

That's why you're being ripped on.

This is why the forum has devolved such as it has.

Between you and Dingo, nothing will sate you. Unless i fire 1 round for every star in the sky, you'll just say ThAz A ThtaSTistiSly InSiGniFicAnT Deeeeeeeeeerp

[AlanF]

...These are the questions that this topic sought to answer. but... a whole lot of energy has been devoted to soothing bruised egos, misunderstandings, manufactured umbrage and deliberate shit stirring.
Meanwhile, we don't have an answer.
Pete

Forums are much better at bruising egos, misunderstandings, manufactured umbrage and deliberate shit stirring than they are at solving complex engineering problems Pete .

[Gyro]

Put it this way PeteF : there was a time long ago when really talented shooters with a competition TRACK RECORD would discuss/debate some really good stuff here. Not any more ! I suspect because people with buggerall experience and/or track record hijack the forum with bla bla bla and no way are the savvy shooters gonna join them.

Way too easy to just repeat what someone else said or did !

The top winning guys know a LOT of stuff.

[Gyro]

All I’m trying to say above Pete is to get an F gun going really well and keep it in that state is NOT easy and it takes a lot of experience to do that.

I have had some moments of success but that is all !!! Seems some here debate this stuff as if it’s really easy to get there. I say they are wrong and don’t understand many things.

The ‘science’ definitely has a place but there’s a lot more to it …

[DingoDeerHunter]

Straw man - no one said anything is easy, in fact the point being made is that it is even harder than portrayed due to the phenomenon of variance.

Looking at World Championship results the lowest Aussie was nearly 100 points under the winner out of possible 660. Wrong node?

What some here assert is that you just bang off some 3 shot groups and you get a reliable guide to performance as between fine adjustments of powder, seating or tiny weight difference at the end of a barrel. they then suggest I am trolling to refer to large sample testing done by credible labs and statisticians indicating these small sample variances disappear as noise.

I find it a quandary, nothing less. Personally I am doing larger sample testing between bigger variable seating and powder charges with random firing order in a manner where I can’t, when testing really know what round I am firing until I get home and look up a reference table. A kind of poor man’s solo double blind test method. Mostly I am focusing on velocity SD and ES and above all safety of the load vis a vis pressure.

Current test is powder humidity and it’s effect on SD.

It’s all good fun really.

[PeteFox]

they then suggest I am trolling to refer to large sample testing done by credible labs and statisticians indicating these small sample variances disappear as noise.

I find it a quandary, nothing less. Personally I am doing larger sample testing between bigger variable seating and powder charges with random firing order in a manner where I can’t, when testing really know what round I am firing until I get home and look up a reference table. A kind of poor man’s solo double blind test method. Mostly I am focusing on velocity SD and ES and above all safety of the load vis a vis pressure.

Current test is powder humidity and it’s effect on SD.

It’s all good fun really.

DDH
the 'Straw Man' comment is unhelpful at best and just pisses people off. Your argument should stand on its merits without that.

At one time I tried the powder charge/node test with five shot groups and got a beautiful flat spot across 3 loads at 0.2gn spacing, so there was a .04 gn window.
It didnt shoot well at all.
I got curious and shot 30 rounds with the 'best' load and recorded velocity at 1 min intervals with a LabRadar.
Velocity was all over the place, can't remember the ES but around 25fps. I would have accepted 10fps as being where I wanted to be over 30 shots.
I then looked at the data as five shot strings, so shots 1~5, 2~6, 3~7 and so on. So within 30 shots there are 26 five shot consecutive groups when analysed this way.
One third of the groups had an ES of 10fps or less, purely by chance, which roughly lines up with the occurrence rate of flat spots on
a velocity node graph and also the spread within each load/node point. remember these velocity nodes are just composed of averages of the 5 shot groups.

This lead me to other things that I think do make a difference
Primer weight
Neck tension
Projectile length - BC consistency
Powder moisture content - older powder sucks, I need a dehumidifier
Projectile jump
all these things do make a difference in my limited experience. - it's all about uniformity.
Pete

[DingoDeerHunter]

You can make a humidity stabiliser using water, sugar and non iodised salt. The ratios will determine the humidity at which the solution will stabilise the sealed environment. Or to just dehumidify you can just put your powder with open lid in a sealed container and a bowl of salt next to it which will suck up water - knowing the humidity can be important (a gauge) as dryer will be higher pressure and could be an issue.

Things like the boveda packs work, they come in variable % from 32 to 75 - but can be reproduced reliably with CaCl and salt slurrys. There’s a formula but you can also just mix up various ratios and measure their effect with a gauge.

Keep ya powder dry as the saying goes. But pressure test at same % or problems can ensue.

I will post my results when I’ve done % v SD/ES testing. Be a couple of months before I’m done.

[PeteFox]

Primer Weight
I'm travelling so I don't have the numbers, but this photo shows the lightest and heaviest primer in 1000 brick of Fed 210GM.

Screenshot_20230901_100500_Photos.jpg

There's a flier there. In the lightest one at left the level of primer compound is considerably lower.
Pete

[Gyro]

Primer Weight
I'm travelling so I don't have the numbers, but this photo shows the lightest and heaviest primer in 1000 brick of Fed 210GM.
Screenshot_20230901_100500_Photos.jpg

There's a flier there. In the lightest one at left the level of primer compound is considerably lower.
Pete

Nice one Pete. I bought a BGC tool today ( Bob Green Comparator ) so hopefully that's worthwhile. I jest !!!!!!

But I did try something from "the good old days" off this forum - 2012 - from one of the winningest of the Oz shooters. I had to read the tea leaves to see a result but them top guys will persist in reading tea leaves because they have done a lot of shooting ( and winning ) so maybe they know what they are on about ? Maybe not ..... just sayn. Cheers Rob K the kiwi wannabe.

[Gyro]

At the range the other day there was a guy doing a seating depth test on his bloody expensive ‘custom’ hunting gun – a full carbon creation. He was shooting what I would strongly suspect is a bullet that will not be easy to get to shoot well. The component manufacturers would love this guy because there was a million things wrong with his setup and he had already fired a lot of rounds and will never ever know with any certainty if he has found a good seating depth. Probably he will just pick the best group that will randomly pop up ?

This an F Class forum but the same basic rules apply regards what you can and can’t know from your groups. So it’s a spectrum. Somewhere along that spectrum are the “Credible Labs” churning out lots of data. Trouble is not everyone agrees the Labs have a ‘credible’ testing setup.

So who are we going to believe ?

[PeteFox]

About powder.
Powder absorbs atmospheric moisture.
This has a two factor effect.
Powder with added moisture is denser than powder from the can, so there is less powder in a given weight to do the job of pushing the projectile because you are also weighing water. So your 50.0 gn of 2209 straight from a new can is not the same as 50.0 gn from powder exposed to the air for a long? period.
Also 'cooking' that moisture out of the powder during combustion takes energy. Whether some of that energy is returned to the system due to creation of steam or is energy removed from the system and not available for bullet propulsion is unanswered.
Either way new powder and powder with moisture added aren't the same thing and will have different burn rates.

There is a good read on the topic here >> https://chronoplotter.com/2021/08/19/ho ... ct-powder/
It's a longish read, but the article is testing H4350 which is 2209 so it has relevence in Aus/NZ.

I'm definitely buying a dehumidifier, but choosing the level of humidity that will keep powder as is, is the main question, because removing too much moisture will also affect burn rate and pressure.
Pete

[DingoDeerHunter]

About powder.
Powder absorbs atmospheric moisture.
This has a two factor effect.
Powder with added moisture is denser than powder from the can, so there is less powder in a given weight to do the job of pushing the projectile because you are also weighing water. So your 50.0 gn of 2209 straight from a new can is not the same as 50.0 gn from powder exposed to the air for a long? period.
Also 'cooking' that moisture out of the powder during combustion takes energy. Whether some of that energy is returned to the system due to creation of steam or is energy removed from the system and not available for bullet propulsion is unanswered.
Either way new powder and powder with moisture added aren't the same thing and will have different burn rates.

There is a good read on the topic here >> https://chronoplotter.com/2021/08/19/ho ... ct-powder/
It's a longish read, but the article is testing H4350 which is 2209 so it has relevence in Aus/NZ.

I'm definitely buying a dehumidifier, but choosing the level of humidity that will keep powder as is, is the main question, because removing too much moisture will also affect burn rate and pressure.
Pete
Pete

Interesting, thanks for the reference - my intention is to bring powder to different humidity levels using different slurry’s in sealed containers and test them for SD and ES with 20 shot strings. Probably between 35% and 75%.

[DingoDeerHunter]

Actually, they tested SD and ES at different RH levels, and there’s no significant result in that respect. It’s great to see stuff like this, thorough science in action. And particularly insightful from a safety perspective - the pressure increase in the very dry powder of circa 3000psi means summer loads compared to winter loads could be quite dangerous if powder humidity is not understood and taken account of when loading.

[PeteFox]

Here is another take on moisture effects on powder, but this time comparing volume measurement with weight measurement.
Not a lot of data, but it does suggest that volume also changes with exposure to humidity.

Part 1. Volume measurement https://youtu.be/uEUrqdBowb0?si=4g6aOVRrFV-HLszA

Part 2. Weight measurement. https://youtu.be/1sEZwzGdILY?si=OyHnIuCyJ577LkH-

Pete