11 Attachment(s)
Seeing the light: A load development case study
"Insanity is doing the same thing over and over again, and expecting a different result" - Albert Einstein. maybe.
I'd like you all to meet Dennis.
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Dennis is an older gentleman, based somewhere in the Southern states of the USA, perhaps Georgia, and the mastermind behind the "Everyday Reloading and Shooting" youtube channel.
https://www.youtube.com/@EverydayReloadingandShooting
Dennis owns a Tikka T3 .223, and a Sako S20 6.5 Creedmoor, and Dennis is a load development enthusiast. Dennis has undertaken many thousands of shots of load development, following conventional tuning processes, videotaped the results, and uploaded them to youtube for everyone to enjoy. This creates, if you can ignore his tortuously-absent-any-factual-basis mis-use of mean radius, a treasure-trove of data for a case study on understanding the effectiveness of those tuning and load selection processes for actually identifying whether any of it makes any difference to rifle precision.
It isn't clear for exactly what purpose Dennis is doing all this reloading. He focusses on creating a series of test loads for some particular combination of components and load parameters, shoots those, then reports back on what results were observed, with a wide range of interestingly meaningless metrics.
Let's have a look at some of these. I highly recommend that you absolutely do not watch these videos and instead read my summary.
6.5 Creedmoor Sako S20
Dennis first determines the distance to the lands for his rifle. He then, using what appears to be a somewhat arbitrary charge weight, seats a range of loads at 0.010" increments deeper starting at 0.020" off the lands. He's using high quality components - lapua brass, H4350, 140gr ELDM, and appears to have reasonable quality reloading equipment. 10 groups of 3 - 30 rounds.
https://www.youtube.com/watch?v=-xBHIKYr6GE
Dennis then goes to the range and shoots these rounds !
https://youtu.be/8c0CnAeNgEU?si=UV4Vfq2BsWH8cAzf
Dennis seems fairly happy with his results.
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What are these results?
Well, his first 3 shots are "barrel warming and fouling". 0.46" group more or less centred on the X- and Y- axis, just a fracco left. He adjusts 2 clicks up from here. When he fires another 3-round group of the same load, it looks about 2 clicks up, but it's moved out to the right about a click. That's pretty normal - POI wanders around a fair bit between 3-round groups, even in a windless indoor range.
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However enough about accuracy, let's look at the group sizes and talk precision
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The variation above and below the mean across these is about plus and minus 70%. That's about what you get when shooting 10x 3rd groups of exactly the same load...
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Regardless of that bit of foreshadowing, Dennis decides that he might be seeing some nodes at 2.872" and 2.812", and decides they require a bit more testing. Fair enough.
So it's off to the range again, this time to "zero in on the node".
https://youtu.be/J_9e6SEOqHo?si=vNFmNiVOgVk48YiA
First up, Dennis re-tests the "node" that produced a 0.24" 3-shot group - 0.020" off the rifling. He does, admirably, test this with a 10 round group.
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For some reason he's mis-labelled it vs his commentary - data management is a bitch - but unfortunately for Dennis, his tuned node at 0.020" jump doesn't produce what he's looking for - just a 1.28 inch 10 round group. Astute observers at this stage might look at the mean radius of 0.43 inches, multiply it by the correction factor of 4.16, calculate that he should expect a 95% dia of 1.78 inches plus or minus about 20%, note that all his previous shots from testing fall into that diameter centred around a common MPOI, and reconsider the approach or expectations. However, not our man Dennis.
Dennis gets onto his next investigative step - testing a range of seating depths in 0.003" increments either side of the other previously identified, um, node at 2.812". No, it isn't clear why he tested one node with a 10rd group and the other with a series of 3-rd groups. What is clear however, is that he's now 63 shots deep in this load development (including foulers) and hasn't yet worked out what he can expect from any of these loads in the future.
Attachment 279520
For some reason his POI has shifted a bit. Alarming. He doesn't seem terribly concerned that the seating node he was testing (2.812") produced a group 50% larger this time than last time (0.45" vs 0.3"), but gets on with it and decides that in fact, 2.815" is the magic seating depth that requires more testing. Happy days.
Dennis loads up a few of those, except for some reason seated 0.001" deeper, and heads back to the indoor range. This time he's framing it as instructional - "how to find the node". Good stuff, he's done a lot of shooting so surely he has found it and can tell us how.
https://youtu.be/anwzFsFGiw8?si=QoLYRRqJ2Y1XeTmI
He bangs out a 3 round fouling group, then a 10 round test group. Nice work Dennis. That's shots 64 to 76 on this load development process if anyone is keeping score. Let's have a look.
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Hmm. At a group size of 1.18 inches and a 0.39 inch mean radius, there's no evidence that it's any different from the other seating depth above. Bugger. Back to the drawing board for Dennis - spoilers - he's going to have a crack at length-sorting bullets.
This next range trip isn't a very long video. Dennis bangs out a few foulers and one 10rd group. And it's looking pretty good, actually, except for....
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...yes, Dennis is very tempted to call that one a flier. Who wouldn't be, after so much effort and 89 rounds of development? The fact remains that if we don't exclude that shot, it is a 1.35 inch group, and the mean radius is inside the range you might expect based on prior groups. Any of these metrics will see some variation around the mean with only 10-shot samples.
Now the chronology seems to get a bit funky with this series. Dennis refers to a video in which he shoots a great 5-shot group with this load. This actually happened much earlier than the rest of this series and it's an odd anachronism. But it appears that some horrible sceptic named Warren (my name is not Warren) challenged him to shoot another 10-rounder with it and see what it looks like. To his credit, Dennis is not afraid to meet this challenge, although it's sort of odd, as he's done a heap of load development since that.
https://youtu.be/wQdPsXPMq4I?si=ZF8SYzSpZFKMG25x
The 5-shot group that inspires this, is this group - it's a quarter MOA. It really shows what the rifle can do, doesn't it?
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So off he goes - back to the indoor range, armed with the usual fouling shots and enough finely loaded quarter-MOA precision rounds, length-sorted, for a screamer of a 10-round group. Let's see how that goes.
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Well, not a quarter MOA. However, Dennis seems pretty philosophical about it and takes it in his stride. Which does make me wonder for exactly what purpose he's doing all this. It's not clear where to from here with this one for Dennis, but we've now got a record of at least 109 shots of load development, a bunch of different tuning and testing nodes. Which has led Dennis to shoot 4x 10 shot groups, averaging 1.28" and varying about .1" above and below that, which is actually more consistent than you'd normally expect for 10rd groups. All the 3-shot groups fired during the testing process fall inside the general cone of fire described by the 10 rounders.
Interesting stuff, isn't it? And I didn't have to spend a single cent on powder.
Who's interested in some more Reloading Adventures with Dennis?
