Very happy so far, “10 round” load development results.

[Ned Ludd]

Your test results look great except for one little thing.

Am I the only one that noticed @Sraw actually used 12 rounds for a "10-round" load development?



With regard to Damon's white noise comment, the way to know for sure is to repeat the test a couple times and see whether the resulting curve looks the same, especially with regard to velocity versus charge weight in the "flat spot" from 42.2 to 42.6 gr. Betcha' it won't. Even 5-shot average velocities fired successively with the same load under almost identical conditions will routinely vary by approximately +/- SD, or from 5 to 10 fps, depending on the cartridge, powder, reloader, etc. It is highly likely that any flat spot observed in a velocity curve prepared using single shot velocity values is merely fortuitous and not repeatable. Fortunately, it only takes 10 rounds (I'm sorry 12 rounds ), to determine whether the curve is reproducible. Regardless of what you get out of this approach, I would say it will not be wasted effort. You're learning as you go and might also end up where you want to be with the load itself. My suggestion would be to pay very close attention to how reproducible charge weight/velocity values are from session to session, or even within the same session. Having a good working statistical knowledge as it relates to various reloading phenomena can be extremely useful.

 

[Sraw]

Your test results look great except for one little thing.

Am I the only one that noticed @Sraw actually used 12 rounds for a "10-round" load development?



With regard to Damon's white noise comment, the way to know for sure is to repeat the test a couple times and see whether the resulting curve looks the same, especially with regard to velocity versus charge weight in the "flat spot" from 42.2 to 42.6 gr. Betcha' it won't. Even 5-shot average velocities fired successively with the same load under almost identical conditions will routinely vary by approximately +/- SD, or from 5 to 10 fps, depending on the cartridge, powder, reloader, etc. It is highly likely that any flat spot observed in a velocity curve prepared using single shot velocity values is merely fortuitous and not repeatable. Fortunately, it only takes 10 rounds (I'm sorry 12 rounds ), to determine whether the curve is reproducible. Regardless of what you get out of this approach, I would say it will not be wasted effort. You're learning as you go and might also end up where you want to be with the load itself. My suggestion would be to pay very close attention to how reproducible charge weight/velocity values are from session to session, or even within the same session. Having a good working statistical knowledge as it relates to various reloading phenomena can be extremely useful.

If we’re being honest here... it was actually 16 because I wanted to start in a known safe zone and see where I found pressure signs. Well I did t find any pressure signs but only loaded to 43.

The reason the graph shows only 12 is because that’s the max my graphing app allows... the first three were 40.0-2562, 40.2-2594, 40.4-2643, and 40.6-2653

 

[dcali]

Here’s something to think about. To get any confidence in your velocity plot, you’re going to need to shoot it more than once. Even three times will likely not show anything obvious. That’s 30 rounds. You can bracket a decent amount of territory (2 charge weights at 5 seating depths each) with 10 3-shot groups, and wind up a lot closer to a good load, in my opinion. It’s debatable that velocity charts have any correlation with accuracy anyhow. I personally don’t believe they do- I think it’s all random and people who see good results with the method are just lucky.

 

[normmatzen]

Ditto what damoncali said!
Both about min 3 shot groups, Statistics is a bitch! and velocity indicates longitudinal resonance only and actual group testing at range is for cantilever resonance. Cantilever resonance is what you develop a load for and adjust your tuner (If you use one) to.
At least for long range bench rest and F Class.

 

[Peebles24]

I have read the 6.5 guys 10 shot velocity loading thing. I did my OCW test with all shots over a optical chrono just to see. I ended up going with the OCW method findings and have been very happy. Here is a pic of my paper from 200 yard with all speeds written on it. Yes it took a lot of trips down the range. Glad i was only person there that day. The top left 3 were used as foulers.

I went with 41.2 then followed up with a seating depth test which ended up at .020

 

[fredo]

I think it's more of a short cut for experienced reloaders that are familiar with a given cartridge and know pretty much where they should end up. More of a verification of an existing 'pet' load in a new barrel/gun than full-on load tuning. Some people swear by it; others swear at it...

Agree!
There's plenty enough reload data floating round the webs, where one doesn't hafta perform a 'full monty' development strategy for many popular cartridges. Odds are very good that a quality barrel will shoot a given bullet/powder/primer combo within a very well known 'window' of charge weight/velocity...
As you eluded to so well, this 'short cut' to load development works, because it uses & relies upon previously 'known' & proven bullet/powder combos within a focused charge weight range.
Those who've wildcatted and/or started from scratch, realize that...

 

[steve123]

I'll say this...

The lowest ES load doesn't always shoot the tightest vertical at distance.

The lowest ES load doesn't always shoot the tightest groups at 100Y, but what happens at 100Y matters little to the long range shooter.

For the long range shooter, all that matters to us is how tight the vertical is at distance, besides getting away with how little wind drift we can get away with/Speed-BC. That might not mean the lowest ES.

Lowest ES might or might not coincide with a barrel node.

Node + lowish ES is where it's at. The top consideration being the smallest vertical that can be attained at distance.

Since I don't want to spend the time and barrel life working up loads(not a BR shooter), and to try to avoid doing multiple ladder tests, I load in .1 grain increments "in medium sized cases". Ladder testing at 400Y or farther, in 20 shots you should see obvious nodes if your rifle shoots decent.

Take load developement as far as you want but... Story - when I first got into long range I tried 3 powders, 3 bullets, 3 primers, hundreds of rounds tuning depths, chronographing, etc. That was 1/5th that rifles barrel life. Shortly after I got the high score by 15 points at our 1000Y match. Will I spend that much time and effort again, no way.

Will I try to deduce ES and a node in 10 shots, nope. Find a balance in this - due diligence, what's 20-50 more rounds to confirm charge and depth??? Well you do have some information with the work you've done so far that can be used.

Owning my own reamer and custom dies and about ready to do my 8th barrel on that reamer, I know with some certainty where the nodes and the depth will be. That helps!

Don't hang a MSchrono off the barrel when you are developing loads. Let the barrel cool evenly between shots, pick a calm morning, lacking bad mirage.

 

[Sraw]

Here are the results from my 2nd trip to the range.

The top are with the chrono on the barrel, the bottom without. The left are 41.5 and the right are 42.5.

Coincidentally the SD on both loads was 13 and the ES 32.

I might mess with seating depth some on the 42.5 and maybe do some OCW testing with 42.4, .5, .6, .7, and .8 though I dont know how much better I can hope for with a factory rifle.

 

[Sraw]

I'll say this...

The lowest ES load doesn't always shoot the tightest vertical at distance.

The lowest ES load doesn't always shoot the tightest groups at 100Y, but what happens at 100Y matters little to the long range shooter.

For the long range shooter, all that matters to us is how tight the vertical is at distance, besides getting away with how little wind drift we can get away with/Speed-BC. That might not mean the lowest ES.

Lowest ES might or might not coincide with a barrel node.

Node + lowish ES is where it's at. The top consideration being the smallest vertical that can be attained at distance.

Since I don't want to spend the time and barrel life working up loads(not a BR shooter), and to try to avoid doing multiple ladder tests, I load in .1 grain increments "in medium sized cases". Ladder testing at 400Y or farther, in 20 shots you should see obvious nodes if your rifle shoots decent.

Take load developement as far as you want but... Story - when I first got into long range I tried 3 powders, 3 bullets, 3 primers, hundreds of rounds tuning depths, chronographing, etc. That was 1/5th that rifles barrel life. Shortly after I got the high score by 15 points at our 1000Y match. Will I spend that much time and effort again, no way.

Will I try to deduce ES and a node in 10 shots, nope. Find a balance in this - due diligence, what's 20-50 more rounds to confirm charge and depth??? Well you do have some information with the work you've done so far that can be used.

Owning my own reamer and custom dies and about ready to do my 8th barrel on that reamer, I know with some certainty where the nodes and the depth will be. That helps!

Don't hang a MSchrono off the barrel when you are developing loads. Let the barrel cool evenly between shots, pick a calm morning, lacking bad mirage.

What is your balanced method?

 

[steve123]

What is your balanced method?

More than 10 rounds and way less than 100 rounds to finish a load.

A few things.

I try to stick with bullets that are not so sensitive to seating depth. A few times now I didn't need to do a seating depth test because the rifle shot so well. I only did the ladder test then literally took those loads and won long range matches.

I try to stay with temp insensitive powders so when the load is developed the velocity doesn't go crazy in wide temperature swings from summer to winter - or out of the node which happens with temp sensitive powders.

I start with one powder, one bullet and one primer, the ones I estimate will give me the best chance of meeting my goals. Most of the time I can find a good load right off just with the ladder test like I described. Sometimes you have to keep working so next is a seating depth test.

A few times I had to jack around with a barrel/barrels working loads which didn't shoot as well as they should have. It was either a lack luster barrel and/or poor GS work. Results were poor from the start. In other words I wish I had not wasted as much time and effort as I did, but it was a learning experience.

Or sometimes a barrel just does not shoot a particular bullet well, a bullet like the Berger 105 hybrid for instance, which has shot great in my other barrels. I tried the 95gr SMK in a goofy barrel and for whatever reason the groups were cut in half???

Over the years I've found that factory barrels don't shoot as good as quality blanks most of the time but there have been exceptions. A friends Tikka and a Cooper M21 both shot 1/2 moa. Most others were moa or more factory bolt rifles.

Again, I'm not a BR shooter, I don't need or strive for 1/4" groups. 1/2" or a little less is fine for me.

 

[David Christian]

What is your balanced method?

@Sraw, I use this method for each new barrel that I spin up. It works! In your first chart I see a few potential flat spots. I would normally pick one of them to pursue further for fine tuning. From your first graph, I might load up 5 rounds at 42.1, 5 at 42.2, 5 at 42.3, 5 at 42.4, and 5 at 42.5. Shoot each group at different targets as well as measure data with your chrono. Does one of them have the tightest group on paper as well as the best ES data? Next step would be to fine tune your jump. Settle on one powder weight then incrementally adjust your seating depth by .003 until your group really shrinks. I usually start with a jump of .010 and test all the way out to .030.

Also, is this a new barrel? How many rounds do you have down it? If new, I have found that I need to keep backing off the powder to maintain the same speed node until 300 or so rounds have gone down the tube. Good luck!

 

[Sraw]

@Sraw, I use this method for each new barrel that I spin up. It works! In your first chart I see a few potential flat spots. I would normally pick one of them to pursue further for fine tuning. From your first graph, I might load up 5 rounds at 42.1, 5 at 42.2, 5 at 42.3, 5 at 42.4, and 5 at 42.5. Shoot each group at different targets as well as measure data with your chrono. Does one of them have the tightest group on paper as well as the best ES data? Next step would be to fine tune your jump. Settle on one powder weight then incrementally adjust your seating depth by .003 until your group really shrinks. I usually start with a jump of .010 and test all the way out to .030.

Also, is this a new barrel? How many rounds do you have down it? If new, I have found that I need to keep backing off the powder to maintain the same speed node until 300 or so rounds have gone down the tube. Good luck!

Ok tried out this this today. The only change was Lapua Brass and small primers. For some reason I picked up a lot of velocity and apparently left the accuracy node.

One thing that I found interesting is the load I identified as having the lowest ES and SD in the “10 round” still does.

There were also 2 instances where 1 shot threw off the es and as quite a bit.

42.3 and 42.4 respectively, I’m considering reshooting these.

42.5 was used as the cold bore and again later as well.

42.2:

2806
2807
2819
2793
2793

42.3:

2811
2808
2828
2810
2808

42.4:

2832
2814
2812
2807
2811

Cold bore 42.5 velocities:

2828
2812
2805
2821
2827

45.5:

2829
2831
2821
2836
2833

42.6:

2841
2828
2815
2838
2825

Feel free to add any of your recommendations. I think I’m going to explore that lower node from the initial test in this same fashion.

 

[memilanuk]

The only change was Lapua Brass and small primers.

The brass change alone would pretty much invalidate your entire testing. Then changing primers on top of that...

Start over.

 

[David Christian]

@Sraw, I completely agree with Monte. Start from scratch as you changed 2 core components with the brass and primer. Your first chart showed that you need to target a velocity around 2,760. I suspect with the change in components you will find a higher node to pursue when you repeat this step from scratch.

 

[Sraw]

@Sraw, I completely agree with Monte. Start from scratch as you changed 2 core components with the brass and primer. Your first chart showed that you need to target a velocity around 2,760. I suspect with the change in components you will find a higher node to pursue when you repeat this step from scratch.

I’ll redo this test with the hornady brass and see what happens.

To answer your previous question about if it is a new barrel or not, I don’t know. I got it used but it could have very few rounds through it based on the look of the rifle but who knows.

I was planning on starting a different load work up anyway with the new brass and another bullet, do you use a similar ladder test to start and then do what you advised or how would you start?

 

[Ned Ludd]

I’ll redo this test with the hornady brass and see what happens.

To answer your previous question about if it is a new barrel or not, I don’t know. I got it used but it could have very few rounds through it based on the look of the rifle but who knows.

I was planning on starting a different load work up anyway with the new brass and another bullet, do you use a similar ladder test to start and then do what you advised or how would you start?

Any change that could result in a different powder burn rate (i.e. new Lot of powder or change in primers), case volume (i.e. a new Lot of brass, or different brand of brass), or variance in bullet dimensions (i.e. new Lot of bullets), necessitates at the very minimum enough testing to determine whether the load is shooting the same as it was before the change was made.

The problem with load development procedures that use a very small number of total rounds is that almost by definition, you're testing fairly wide increments in order to cover a sufficiently wide range. Without further fine increment testing, you'll never really know where in the "window" a coarse increment load actually is. Is it right in the middle of the window? Is it right on the very edge? Obviously the latter case will be more prone to going out of tune as conditions change.

There are a variety of charge weight tests including ladders, OCW, etc. Although there are subtle differences in the testing methods, they are essentially all looking at elevation in response to varying charge weight. Both can work. BR shooters tend to favor the ladder approach. F-Class shooters tend to use either (both) approaches.

Ultimately, the key to successful testing may not necessarily be which approach you choose, but how carefully you carry out the testing and interpretation. Clearly the discipline you intend to shoot should influence your choice of methods. But it's also important to point out that with any method, testing increments cannot be too coarse, or the information you get in return is limited at best (i.e where is a given load actually located within some optimal window?). On the other hand, testing exceedingly small increments on the first pass when all you're really looking for is the right neighborhood to test further can sometimes be a waste of time and effort. I think most people try to find an acceptable balance between the two, and it may take time and experience to know in advance where that balance may be.

Regardless of the approach you choose, your initial charge weight testing should cover a sufficient charge weight range to reveal at least one potential accuracy node, maybe two or more. So you can certainly use a coarser charge weight increment such as 0.5 gr to cover a wider overall range initially and minimize the total number of rounds necessary. Regions that look promising can then be tested further in small increments to better define the boundaries of any "optimal" window you find.

Even if I don't use it, I understand the reasoning behind a "10-round" load development approach. I also have no doubt there are those that have been very successful and satisfied with this approach. However, I have gotten the feeling as this thread has progressed that you are becoming more and more lost with the process of load development. Maybe it's time to think less about the total number of rounds used for testing and focus more on a methodical stepwise and incremental approach, regardless of how many rounds it takes.

Your groups at 42.5 gr above give you a good starting reference point, even if you decide to change brass. For that reason, I would suggest trying to reproduce the 42.5 gr grouping and velocity. Changing brass will likely change case volume and therefore pressure/velocity. However, the expected changes shouldn't be huge, as 2-3 gr. It's far more likely you will observe a more subtle change. So use your 42.5 gr load as a reference or starting point, and test in finer increments (maybe 0.2 gr per test point) on either side of that, making sure you cover a sufficiently wide window in the process. I doubt you would need to test more than about 0.6 gr to either side to fully cover the window, even if it has shifted slightly to one side or the other due to using the Hornady brass. Further, your previous velocity at 42.5 gr will also be a good indicator as to what the switch to Hornady brass accomplished. Unless I'm mistaken, the Hornady brass should have greater case volume than Lapua. Therefore, you would anticipate achieving slightly lower velocity at a given charge weight. If that assumption holds, you'd know right away that you're going to need more than 42.5 gr to hit the same velocity, and can adjust the test window accordingly, if necessary. Once you find similar grouping with the new brass, you can move on to a seating depth test, at which point you ought to be close to where the rifle is shooting optimally.

 

[Had2muchofForums]

I would not trust one shot per charge weight. I've performed this test with one shot and three shots per chargre weight. The results did not match up with one another. If you are going to use chronograph data, you need at least three shots/charge weight to find an average. Then look for a flat spot.

 

[Sraw]

@Sraw, I completely agree with Monte. Start from scratch as you changed 2 core components with the brass and primer. Your first chart showed that you need to target a velocity around 2,760. I suspect with the change in components you will find a higher node to pursue when you repeat this step from scratch.

Ok, went back and reshot the same loads with the same brass and primers, here is what I came up with:

The barrel must not have been broken in yet because these were faster too.

I dont know what was going on with the scope but the poi shifted between yesterday and today, that’s the first group, I just adjusted lower and to the left and went with it for this testing. Other than that brief issue, there is no real difference between brass.

One thing I’ve learned is that “10 round load development” pointed me in the right direction, is it perfect? No. Coincidence? Maybe. I’m probably going to play with the seating depth at 42.5 and see where that takes me.

I may also explore the lower node as well.

As always, please feel free to give me any advice or point me in a direction you think may help.



This time I got the following:

42.2:

2819
2800
2812
2819
2798

ES-21
SD-10

42.3:

2811
2820
2814
2830
2811

ES-19
SD-8

42.4:

2823
2835
2836
2824
2832

ES-13
SD-6

42.5 (cold bore):

2852
2830
2833
2830
2836

ES-22
SD-9

42.5:

2830
2820
2817
2825
2824

ES-13
SD-4

42.6:

2855
2835
2826
2830
2838

ES-29
SD-11
(If you take the 55 out it makes the numbers a whole lot better)

 

[Dusty Stevens]

From my observation, and your unexplained poi shift from a different day and those group shapes, youd be way money ahead and cut the learning curve by investing in some wind flags. Perfect practice makes perfect.

 

[JFrank]

May I ask why 42.5 over 42.6