Scientism, the new religion. Do you chase the lands while senselessly burning out barrels, or merely claim that a load now gone out of tune is proof your sacrifice to your statistical god was sufficiently self-aggrandizing ? Pattern recognition has served us well the past million years. Some are better at it than others. Dunning-Kruger is in the house. Your strident arguments including false hope and faith are clear evidence of a lack of talent.
3 shot group vs ladder tests
- Thread starter JoeInTucson
- Start date
I haven't seen Litz and Neville in the same video before, but having a specific ONE video you mentioned, can you spare the effort to cite it? I must not have seen it.
I certainly can appreciate that folks might not like any of their info which peels back the curtain and reveals the Velocity Curve to not be the Wizard of Oz and instead, just be an old man with a megaphone, but as I've stated several times - I continue to wait for someone to provide ANY defensible conflicting data which indicates opportunity for dissention, rather than simply promoting the same low round count, indefensible results which dig deep into the noise of their ammo to pretend a pattern emerges.
Read the thread.
I don't senselessly burn out barrels - so much to the point I don't waste time, ammo, or barrel life shooting Satterlee curves...
Yes, many of us are better at it than others - recognizing noise as noise rather than begging it to be signal is part of that task.
Provide any data or analysis of the provided data which argues against the results I've shared. It took me just over a minute with a cell phone to dissect the reported results and undermine the hypothesis that the low round count data ensures the flat spots must be truthful instead of "inherent noise." Surely it should be easy for someone to refute that analysis, right? If there is so much data out there which supports defensible repetition of flat spots within these velocity curves, why is nobody willing to bring forth that data? We can all be smug AF and shove Hornady's face in it, and force Litz to publish a new chapter in Vol IV which recants an entire chapter from one of his books the moment someone steps up and provides the data - which so many folks keep insisting already exists... But nobody wants to bring it to the public eye to teach us, once and for all, that flat spots in velocity curves are defensibly real, surviving the rigors of applied errors (ES and SD) for more than 75 seconds of analysis by a relatively poor statistician...
I really don't care who is right, I just find the pursuit of precision to be interesting, and I never want to waste time chasing rabbits which don't get me fed - and I know when it comes to the Satterlee Velocity curves, someone stepped on a scale to prove their weight, and the rest are standing in the crowd, far from the scale, and saying they have heavier evidence...
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Well with my minimalist approach to load development i tuned a load in March to shoot at Freedom national in April of last year, I shot that load clear to the end of August without any tweeks to seating, charge, or neck tension.
This load shot cleans with a 80% X count
In our local club matches.
August in Southern Oregon is HOT as hell, compared to our 50-60 degree days in March.
Believe the targets!!
This load shot cleans with a 80% X count
In our local club matches.
August in Southern Oregon is HOT as hell, compared to our 50-60 degree days in March.
Believe the targets!!
CharlieNC
Gold $$ Contributor
All i can tell you is that it was one of the many in the Hornady series regarding load development.
While it's not likely to find a velocity "node" due to the baseline SD and physics involved, I typically find an optimization on the target for seating depth and charge weight using 3 shots per cell X 9 cells using a central composite factorial design. The statistical analysis of the results distinguishes the signal vs the experimental noise, not vs all of the other non pertinent factors which arise from the Litz/Hornady baseline approach.
We have Litz's methods published, do you have access to that of Hornady? Are they using the same methodology? I've never seen the actual testing method used by Hornady.
I've only seen their dissection of confidence, which is not terribly advanced statistics, but does reveal to anyone familiar with these methods as to why we really can't take faith from 3 shots - especially when we KNOW a great SD from our 10-20 round strings is 4-7fps, and each data point on the velocity curve has to be positioned in a specific 2-3fps band to produce either a ramp or a flat spot... We KNOW our SNR is very low, in that analysis.
In general, and maybe it's a cynical view, I'm actually prone to expect most of us are always stuck using philosophy more close to CCD rather than FFD anyway, even when folks attempt FFD - simply because we don't have control over too many aspects of influence (roundcount on the barrel, roundount since cleaning, differences in individual barrels, environmental conditions, etc). But I really think it's much simpler than that - this acknowledgement of the population noise vs. the variable dependence of the results is where most of us are simply lying to ourselves, and there's just no way around it. If we move any data point by 5fps on any of our flatspots (let alone floating ALL of the data points around by 5 fps, in either direction), faith in the flat spot dissolves really, really quickly. How many 20 shot groups have any of us shot which had an ES less than 10? Hell, it's rare enough to see 20shot SD's less than 5 (+/-5fps SD = 10), let alone the reality that ~1/3 of our expected readings should be OUTSIDE of +/-1SD. When our SD is say, 5fps - Standard Deviation, meaning the standard value which each value deviates from the average for a given sample set - how are we supposed to trust that any data point is really within the 1-3fps we need it to truly represent to make a flat spot survive?
Another good example a guy offered me once when he was trying to convince me the Satterlee Curve didn't survive - what happens if you shoot 3 strings (which are usually shot round robin, one of each charge), and you see those "recurring flat spots," but then you randomly remix the shots of each charge into synthetic strings? We shoot round robin to randomize the results, so random velocities for each charge weight SHOULD be able to be intermixed together and repeat the flat spot, right? So why if we randomize the speeds for each shot within a charge weight, why don't the flat spots persist?
ELR LVR
Silver $$ Contributor
This phenomenon needs to be taught in high schools these days.
Recognizing it is the first step to recovery
Several fun rabbit holes mentioned. Sd/Es correlation with group size at various ranges. Lesser slopes in velocity per incremental charge which may or may not correlate with accuracy. Smug is an understatement of the disgust with Hornady’s marketing-driven statistical hack, summary of which is “ buy their factory stuff”, as nodes are a “myth”. I don’t waste either. 10 shot Audette, take the center straight to 1K 3-shot ladder, done. Chrono only for ballistic calc. Positive compensation easily documented in a given system which is constructed for it, seems to peter out at the extremes, where tight ES is mandatory. Cf and Rf. Return on the investment is the enjoyment of deriving meaning. Rabbits happy.
CharlieNC
Gold $$ Contributor
Hornady has a youtube channel with many videos on this topic which you can easlily find.
Have you ever conducted an actual DOE? For example if one wanted to know if 0.2gr of powder affected the velocity, he would not simply load one or more cartridges and chrono that and compare those results to the historical velocity found across a period of time ( which would be extremely variable due to ambient factors, etc). A prudent experimenter would load one or two at 0, +/- 0.2, and +/- 0.5gr and shoot them at once to define the effect; in this case the statistical test is to determine if the slope of velocity vs charge is different from 0.
The same applies to testing shot dispersion experimentation. The variability (SD) of group size over time is the sum of all of the components inclucing rifle, load, shooter, and especially ambient conditions, etc. If one only wants to test whether a change in load has an effect, the effect of those other factors should be minimized. For example one would not shoot one load today, another tomorrrow, another the next day, etc and then compare the results. That defies the logic of experimental protocol.
You can see my treatsie on this topic here, and critique as you see fit.https://forum.accurateshooter.com/threads/target-statistics-for-shooters.4128959/
I think you watched a very different video series than the rest of us.
Yes, this is what we're doing, relatively inadvertently, when we shoot the Satterleee/Audette Velocity Curve.
Unfortunately, we all just started with the misguided premise that flat spots should emerge, despite standing science, even 60yrs ago, that they shouldn't.
I don't agree, however, that the "prudent experimenter" would only load 1 or 2, with the exception of the rankest preliminary experimentation to determine future activities, as population noise must be determined to properly design the volume of work to be done (OR, of course, we have to rely upon statistical references which point to confidence intervals and standardized prediction models to determine range of potential results based on insufficient sample data). But in general methodology, yes, wanting to know the influence of charge weight on velocity, I've done that specific experiment as you just described many, many times, a few of which I shared on pg 1 doing exactly the experiment you described...
Steve Donlon
Gold $$ Contributor
I agree. The last load work I did was three five shot groups with a rifle I had only shot a couple of times and was a gift. I was shooting a group in the .1's. after 15 rounds with one seating depth. .020 off and three different powder charges. It was the lowest node that shot best.
Jeff Porter
Gold $$ Contributor
The Hornady podcast / YouTube’s are titled “ Your Groups Are Too Small”. Two specific to this topic. They also have a couple of more recent ones where the PRS shooters on staff talk through their load development and reloading processes.
Gotta link ?
Excuse me if I missed it but what is your current load development ?
That's the original one most have already watched.
Jeff Porter
Gold $$ Contributor
Episode 52 is the follow up
Hey so what is your load development and to possibly make it more detailed say for a rifle and a cartridge your not familiar with? Just say an average feller
I like your no nonsense approach to alot of your post and sorry if there is a consensus for load development on this forum .excuse my ignorance if so.thanks in advance
For PRS loads, we can largely throw darts at a board, anything Dasher + Varget + Lapua + 105H’s = good enough. For my 2 mile rifle, I shot a pressure ladder, since there’s really no book data for it, which let me figure out where things get sticky (and that my first 2 barrels were fast AF compared to other shooter expectations). Tweaked neck tension a little to make round groups at 1k, and took it to work at 2 miles. I had to move my bullets out after 500 since I want to be jammed, but that’s the only tweaking I’ve had to do.
I don’t waste ammo on tests/load dev steps that rely upon differences smaller than the standard noise in my groups.
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