Thread: A superb article on why "node load deveopment" is toast

Originally Posted by veitnamcam

So to summerise after watching the hornady podcast a couple of times and reading the link at the start of this thread then load development should go like this.
Correct me if I have this wrong please.

Select a bullet and powder you want to use and load enough to get the speed you want at some random distance from the lands.
Load up 20 rounds and shoot at one target,this may have to be slowly for barrel heat/suppressor heat.
If the dispersion is not to your liking don't bother changing powder weights or seating depths.
Change the powder type and re test.
If after trying a few types of powder dispersion is still not to your liking change the projectile and re test.
If after testing a few different projectile and powder combinations you cannot get dispersion you are happy with you may as well change the barrel because no amount of fafing around with seating depths or powder charges will turn a 2moa shooter into a 1moa shooter (for 20 round+ groups) ?

Correct. I'd buy bullet sample packs and change bullets as soon as the dispersion is "outside limits". You gonna know this inside 12-15 rounds.

Originally Posted by veitnamcam

So to summerise after watching the hornady podcast a couple of times and reading the link at the start of this thread then load development should go like this.
Correct me if I have this wrong please.

Select a bullet and powder you want to use and load enough to get the speed you want at some random distance from the lands.
Load up 20 rounds and shoot at one target,this may have to be slowly for barrel heat/suppressor heat.
If the dispersion is not to your liking don't bother changing powder weights or seating depths.
Change the powder type and re test.
If after trying a few types of powder dispersion is still not to your liking change the projectile and re test.
If after testing a few different projectile and powder combinations you cannot get dispersion you are happy with you may as well change the barrel because no amount of fafing around with seating depths or powder charges will turn a 2moa shooter into a 1moa shooter (for 20 round+ groups) ?

More or less. Some additional steps

Adjust expectations of what "good precision" is
Consider using a better measure for your precision (not entirely necessary if you shoot 10+ round groups)
If you want good precision, stack the odds in your favour and get a good system (rifle/scope) to begin with
If you want good precision, use the best components.

Originally Posted by gimp

More or less. Some additional steps

If you want good precision, stack the odds in your favour and get a good system (rifle/scope) to begin with
If you want good precision, use the best components.

I had done that I thought tho I think I may have used too fast a twist barrel....So I have replaced it and am keen to find a good load with minimal round count on the relatively short barrel life of the chambering.

Ironically the best precision shooting rifle I currently own is also the cheapest I own ...Factory Howa bought second hand for 700 bucks shooting cheap gamekings and vmax.

Originally Posted by veitnamcam

I had done that I thought tho I think I may have used too fast a twist barrel....So I have replaced it and am keen to find a good load with minimal round count on the relatively short barrel life of the chambering.

Ironically the best precision shooting rifle I currently own is also the cheapest I own ...Factory Howa bought second hand for 700 bucks shooting cheap gamekings and vmax.

Dropped off some beer on way trout fishing this morning. The owner asked what happened last visit. Confirmed a kill with "cheap" gamekings on his new native block plantings. When are you coming back he said. Go cheap game kings. LOL.


'

TLDL: (if I listened correctly)

Seat bullet 25 - 35 thou off lands (although this not really important)
Choose bullet appropriate for your purpose (maybe have second and third choice)
Choose powders that will push bullet at MV required to do what you are trying to do
Shoot 10 shot groups with your bullet of choice but with different powders
Choose best groups, shoot 20 shot groups of each.
If still unhappy, change bullet, repeat.
If still unhappy, change barrel or change expectations.

That is an interesting article. I've just been to a conference where most of the papers presented focused largely on statistical methods. Statistical analysis requires a good dataset, and a sample size of 30 is where statistics start to become reliable and meaningful. It also empties wallets and bruises shoulders, potentially introducing a new source of higher standard deviation! However, there is still the cold bore shot that will deviate significantly from subsequent shots, and a sample if 30 of those will also be needed to fully understand that too.

Practically, you don't need big sample groups, if you only desire minute of pie-plate groups to knock down a deer at 100m. While you may not be getting the absolute best out of your rifle, it will meet your needs just fine. If you have OCD, or are a precision shooter, then statistics opens up a world of challenges!

Originally Posted by davetapson

TLDL: (if I listened correctly)

Seat bullet 25 - 35 thou off lands (although this not really important)
Choose bullet appropriate for your purpose (maybe have second and third choice)
Choose powders that will push bullet at MV required to do what you are trying to do
Shoot 10 shot groups with your bullet of choice but with different powders
Choose best groups, shoot 20 shot groups of each.
If still unhappy, change bullet, repeat.
If still unhappy, change barrel or change expectations.

Sort of. I would amend to say - test the bullet you want to use with the powder most likely to work, and if the result is acceptable - stop there and use it. "Best" or optimisation approaches are Sort of a waste of time and resources compared to an approach of just looking to meet a required standard.

I agree with Gimp.
With my flintlock I chose 3F powder and the bullet was round soft lead. I got it going at 1800 feet per second and can shoot three inch groups at 100. These were my premeditated standards - when I achieved them I accepted them. It took three shots. (It's a flintlock. That took an afternoon.)

A Russian taught me a saying once: "Perfection is the enemy of good enough."

Originally Posted by gimp

Sort of. I would amend to say - test the bullet you want to use with the powder most likely to work, and if the result is acceptable - stop there and use it. "Best" or optimisation approaches are Sort of a waste of time and resources compared to an approach of just looking to meet a required standard.

Agreed, there is a forum member, who when Brian, Tahr and I were were working on half inch groups declared after a 2 inch group with his .270 said, that will kill deer, and he did and kept on doing it doing it there after.

Originally Posted by gimp

The thing is that I'm really interested in the "average" numbers - not the winning numbers, or the records. The winners and records are by default outliers. The winner or record is the best - that excludes all of the other data from the sample. What does that tell us about the whole picture?

To test "whether load tuning works", you can't just cherry pick the absolute best results from a population of people that are all tuning and say look, good groups, it works, don't look at all the rest of the data. Those who are losing BR matches are also tuning - so therefore it doesn't work? Is it that only the "best at tuning" are doing it right and winning - so it's only worth doing if you're the best at it? But then they don't win every time. If benchrest competitors are losing because they're tuning wrong, how likely is it that it's worth a hunter bothering with it for a hunting rifle?

To prove there is a difference you actually need to try measure whether there is a difference - pick an "in-tune load" and shoot a meaningful sample,and pick an "out of tune load" and shoot a meaningful sample, and see if there's actually a significant difference.

We know that "agg" or average group size is not representative of the actual precision capability of the rifle. I have shot 4x or 5x 5-shot 100m group "aggs" of under 0.5MOA with my 8lb .223 hunting rifle, with un-tuned loads loaded in bulk 1x fired factory brass FL sized in cheap hornady dies with no special prep, with VLD type bullets seated a random distance off the lands, powder charge selected at random to be "about book max" , shooting prone off the ground with a hard hold from a bipod and bag, no wind flags, 2lb trigger, shooting on 15-18x mag, etc, more than once.

The actual precision of the rifle when the groups are overlaid is of course larger than 0.5moa, and the 0.5 moa agg doesn't tell us anything predictive about the precision of the rifle - it tells us it "shoots well" but isn't informative for understanding what size of target we might be able to expect to hit.

If everyone is tuning loads, then the value in it is only as good as the worst or average results - and it looks like I'm not that far different from the worst results without doing it - but I'm also shooting with a lot more uncontrolled variables so it's a pretty crap comparison. I'm not shooting BR winning group aggs... but I can sure shoot some BR losing group aggs !! It would be really interesting to see competitors shooting similar equipment, rests, loading process etc test the actual validity of the tuning process - is there a real gain to be made from tuning powder charge and seating depth? there might be - but it seems extremely likely that it might be something tiny and only able to be resolved with exceptionally precise equipment and technique.

Here's some randomly selected google results from some sort of BR nationals in the USA for the last 2 years - the losing aggs at the 100Y distances are around the high 0.4-0.5MOA range - mid pack looks around the high 0.2-0.3 range.

https://internationalbenchrest.com/a...0Nationals.pdf

https://internationalbenchrest.com/a...%20Results.pdf

You will notice in Benchrest there are a small number at the pointy end and a spread in the middle then a small number at the tail end.
While everyone "tunes" by adjusting powder, seating depth and neck tension some are better at it than others and some are better at reading the wind than others, and some barrels and rifles are better than others, also some bullets are better than others.
Given the "blunt" 6mm bullet all Benchrest shooters use, the wind does affect them and it's quite often you will see a 4&1 group with the 4 in a small hole and the 1 quite a ways away from the other 4. wind, handling errors etc can affect the group size.
Over the last couple of years I have seen where the winner shot a .5agg and the largest agg was 1.3", yes conditions, wind, rain etc do make a different to the results.

But with a good Benchrest rifle when tuning you can see the difference in powder, seating depth and neck tension by firing 3 shot groups and it's repeatable.

This is harder to see with factory rifles and a consistent .5moa out of a factory rifle is really good

As you say the records are outliers, but they aren't that far off the average winning aggs.

Most only believe what they want to believe, the best way to find out what a good Benchrest rifle does shoot like, and the difference seating depth & powder make is to experience it over several competitions.

Originally Posted by Tahr

Ive mucked around with neck sizing but for hunting the security of knowing every round will fit the chamber is reassuring.

My load development has always been random and unsophisticated. Work towards max pressure at mag length from mid range with a couple of rounds for each load and then back off a bit when I see a sign of pressure like a change in the primer. If it groups "good enough" there job done, otherwise I pick one of the 2 shot groups that looks the best and settle there.

Sometimes I get it spot on with little groups. Sometimes hovering just under an inch for 3 shots. I don't over fuss. My head wont let me settle for anything under an inch though.
If I miss an animal from there on out it certainly isn't the load's fault.

Some of this load development stuff can be too heavenly to be of any earthly use. But I do understand the fascination.

Sums up my process too. If I dont get the velocity I want and accuracy Ill change projectiles rather than stuff around looking for some magical thousandths of an inch or .1gr of powder.

I used to think I was charmed as my rifles always shot as well or better than my mates who spent hours working this stuff out. Turns out I am probably just part of the noise.

I suspected Santa wasn't real