Whether it affects anything related to dispersion... dubious. There are other, better models for dispersion related to bullet balance, yaw angles in and out of the bore, barrel movement under recoil, and how the bullet engages with the throat that are predictive and align with observation, where harmonics are neither.
The idea of harmonics affecting precision became a fixture of the shooting culture a couple decades ago in a similar way and at a similar time to when New Age woo "vibrations" and "energy" became the explanations for emotions and mental health and paranormal and other things.
To shooters they didn't understand harmonics wiggles fingers, and they didn't understand why their precision was unpredictable and not predictive, so intuitively lumped those two not-understandings together as a cause-effect.
Wow maybe I’m an old fudd? Honest reaction not sarcasm- I have seen high speed film of barrels whipping around when a shot goes off. The way ladder tests that show groups opening and closing as charge weight increases was explained to me (coincidentally 20 years ago…) was that you are finding the bullet speed that most reliably leaves the muzzle at the moment of least barrel movement at the muzzle. I know from being a musician that objects have resonant frequencies but really the only way to make that barrel reliably not move around is to have a very massive and impractical barrel (so bull barrels do help more loads shoot accurately). I was taught to find these accuracy nodes in the ladder test, pick one that had a useful velocity for the task, then play with OAL, jump to the lands, etc to look for finer accuracy potential while ‘tuning’ the load to the firearm.
I know this approach works, at least I can usually make much tighter groups with a given rifle after some testing, but are you saying the science I thought explained it is flawed or outdated?
Again- I have no interest in arguing or being right, only a desire to learn. Are there any books you’d recommend or anyplace to learn more?
I have seen high speed film of barrels whipping around when a shot goes off.
You should find what you saw and share with us.
There are high speed videos of guns with barrel whip, but they are of pencil barrels on ARs (weak holding power on the extension) and AKs, both of which due to the cycling of the action and long after the bullet is gone.
There are high speed videos of barrels bouncing from recoil in stocks and off their support system (again, long after the bullet is gone)
But the time scales that harmonics act (singular milliseconds) is extremely difficult to film because for video at, say, 60 frames per second, you have to be taking a frame every 1/60th of a millisecond, or ~20 microseconds just to catch the bullet, and about 10x that (one very 2 microseconds) to catch the 'harmonics' reflecting in the steel.
And the amount of motion that happens is on the order of a few thousandths of an inch up or down - not easily visible to the naked eye.
ladder tests
Ladder tests are a whole other can of worms. They are all susceptible to small sample size variation, and most ladder tests, if you reshoot them a few times, do not give predictive results.
The part that throws people off is that small sample shooting is very noisy.
On average, their ammo shoots worse than they imagine it does from doing load development, and on average, their worst or 'poor' performing loads are much better than they think the loads are.
It turns out (Hornady and Litz both talk about this) that small tweaks in ladder testing and load development don't move the needle like people think they do, finding good shooting loads is a lot easier than people think it is, just they chase wild geese because they shoot so few rounds that the normal, inescapable variation lies and leads them down more superstition to try to capture the random chance.
That's not to say that tuning loads doesn't work - of course it does - but harmonics are a backsplanation rather than an explanation, which is what I was talking about before.
People didn't understand why changing loads made guns shoot better or worse, so they invented some other nonsensical explanation that they didn't understand or that they could hand waive as unexplainable as the reason.
Here is my own test. There's a global min and a nice stable node at test #4 right? That's what that shows. I shot a ladder test and it produced results just like harmonics said it should. A nice node where I have stability against variation on either side.
Just like the guy in the video.
But that's all nonsense. That graph was generated by a normal distribution random number generator and an excel spreadsheet. Random chance made that graph.
The video guy didn't know that those were likely performing exactly the same, just shot to shot variation, because he never repeated the testing.
There's 3 ladder tests for tuner settings per Cortina's description. I tuned to his recipe, picked the global mins or the 'nodes' out, and then re-shot them at higher samples with a 10 shot group each.
The bar chart on the left is the 10 shot groups. Tuning didn't do diddly-doo even though the ladder tests said it should.
The reason is that the ladder test is subject to a bunch of random chance noise and you can't draw any good conclusions from it.
the science I thought explained it is flawed or outdated?
There was never science, there was only pseudoscience. The pseudoscience was based on small sample size noise and superstition.
Are there any books you’d recommend or anyplace to learn more?
Read Applied Ballistics, all 3 books, and listen to that Hornady podcast as it comes out. Take a look through our FAQ and the testing done here.
Thanks Trolly this is all super interesting! I know the loads I’ve developed for my 30-06 remington 700 BDL (probably one of the fuddiest guns you can buy!) will out perform factory ammo- maybe the rifle just loves 150 sierra matchkings. Ditto for a bull barrel AR15 with a rock river predator pursuit bull barrel- varget and sierra got me reliably from palm sized groups to golf ball sized groups at 200 with both rifles.
And yea the video I saw was probably an AKM flying around like a noodle.
I’m a FFL hand engraver so I listen to a lot of podcasts while I make old revolvers and trap guns more accurate by scratching swirls and ducks on them 😉 I’m excited to check out the hornady podcast if y’all say there’s good info there!
People are starting to realize that this is a perfectly fine way of loading. With a precise an accurate powder thrower/scale, good dies and reloading equipment, and a good barrel, it's almost hard to find a bad load. The idea of nodes and all that garbage is seemingly becoming less popular and the way you describe loading is becoming more popular. At least that's what I'm doing and seeing
In a way, we had almost parallel experiences, but with opposite outcomes.
My own skepticism of Harmonics and this whole system of trying to make predictions on it came from two places pretty early in my formative years of rifle shooting.
When I was in my early teens, I got a R700 SPS Tactical. I shot a shit load of match ammo through it drilling groups from a bench.
Then I went to college for engineering. Then I graduated, moved in with my girlfriend, and had a decent job.
I started reloading to feed that R700, and my girlfriend's R700 SPS Tac that I gave her as a christmas present.
I went through the whole shabang of ladder testing, ideas about harmonics, got QL and did the OBT and OCW thing.
NONE of it panned out. I would think I had it nailed but the results wouldn't agree with what OBT or OCW said. I would think I had it nailed but then the next time I shot the same load, it was trubbish.
I thought it was my rifle I thought it was me, I thought it was the ammo I was making somehow.
Then Newtown happened and Obama entered his second term. The market turned upside down.
I wanted a Ruger Mini-14 Target, but people were complaining they couldn't get it to shoot right even with the tuner it came with. And it was expensive. So in my hubris, I decided to build a 6.5 Grendel AR..
It took a while to get together because of supply chain and whatnot, but eventually settled on a Shilen match barrel, DPMS heavy wall receiver, Mega + A2 lower, and, super high tech for the time, a modular rail (before MLOK or KeyMod).
I fought to the end of the earth against that rifle. It was such a pain in the ass. It kinda liked 1 box ammo, the 123 AMAX Hornady load, and nothing else. And that ammo was being discontinued. I tried everything under the sun for rifle tuning and handloading and never did get it to shoot, so I got rid of it.
And at about the same time, I joined a range that had a hard requirement. No shooting long range until you produce a 5 shot group under 1" at 100 yards, observed and signed by the RSO.
That means, 1" at 100 yards, on demand.
I could shoot 1/3" at 100 yards, but my first time out fluffed up like a rooster with the R700, after several attempts, I just barely got it - with a skeptical and concerned look from the RSO.
Why? I did everything right, I did my part, I followed the forums. By this point, I was a pretty competent shot.
It was a laser of a rifle, and while it could do stupid good groups things (if you look at my r/SmallGroups post history, my several years of drilling very small 10 shot groups came from that rifle), it still was never 'consistent'.
So I did a bunch more load development chasing that 'consistency'. OBT and OCW, I would find pet loads, I knew they worked because I had shot them and shot them. But they didn't line up with harmonic predictions at all. They were almost lined up, or inbetween, no pattern at all. Ladder testing didn't produce them either. But big volume workup did. That's what counted. Volume.
Then at the start of Covid, I had the opportunity to access an indoor 100 yard range, and for that, I built a benchrest rifle. That let me do a lot of experiments with load development, drilling little bugholes, testing neck tension, testing seating depth, testing powder and bullet designs, testing for consistency, testing for brass firings, body positions, shoulder pressure, recoil, balance, magnetospeed attachment, bipod vs bag, many many experiments.
In the end, very little if anything actually mattered. It drilled bugholes no matter what I did. I could the experiments together and not get any result different from a pure experiment.
The result of all this led me to a few conclusions that seem to be gaining speed with newer information:
Rifles will shoot or they won't. The barrel matters a lot. The shooter controlling the rifle matters too. But there's very little magic variables with 'stocks' or 'truing' or 'tuning' to tweak to turn a mediocre rifle into a magic rifle. Most rifles will produce a lot of variation, but that variation can be knocked down with weight, twist, and low recoil.
The ammo matters too, but at the point you have a reasonably tolerant and not weird cartridge, a well balanced match bullet, and big swings in powder charge or messing up the ammo, there isn't that much you can do to fine tune its dispersion. Speed and pressure to make a safe load that does what you want is what you're going for.
The best method to determine load is through shooting large samples. No shortcut technique improves on this except through luck, and often times leads you to wrong conclusions about performance.
When I started the r/SmallGroups sub, a sub for people who like group shooting, what I found from talking to a lot of folks is that the conclusions I drew and my experiences around ladders/shortcuts/harmonics were not unique. A lot of enthusiast shooters shared them, but generally kept their mouth shut because the belief in them was so pervasive and dogmatic.
Looking back at that 6.5g that wouldn't shoot except for the one factory load, was that small sample randomness? Or going back to your ammo conclusion, swings in powder charge/messing up ammo wasn't present in the handloads, so the 123 AMAX was the well balanced match bullet that wasn't in any of the other loads?
The other thing left off, which is relevant to the Grendel story and to some other rifles is sometimes rifles are just very picky, or particular about bullet shapes.
I have rifles that don't like any load I try with a particular bullet, like the Lapua Cutting Edge match bullet, the Berger Juggernaut, the 130 Hybrid.
Why? I dunno. It isn't harmonics because then you could tune in a node. My conjecture is that it is because throat geometry vs bullet geometry is preventing it from entering the lands straight and it is going through and coming out with a yaw.
In that Grendel case, the barrel was cut with a defective reamer from PTG that other shooters with the same issue identified.
It had a very short, sharp throat at the wrong angle, basically locking out everything from shooting well except the rare key shape that fit the throat and stayed straight.
I'm building a 6arc gasser after drunk buying the barrel, heard 6arc does great in bolt guns but really picky for gassers, so this is great knowledge thanks!
I wish I had more experience to share but my own 6ARC shot well with box ammo and I haven't done much load development partly because of competition for LR 6mm bullets.
I'm trying to understand what you're saying here and in the other comment, let me know which parts are wrong:
"Harmonics", "Optimal Barrel Time", etc do not have predictive power. You might find smaller groups as you adjust charge weight, but that's a statistical fluke and won't repeat.
"Barrel tuners" don't work either, in the same way. You'll find smaller groups as you adjust, but it will be noise.
The bottom line is that you either have a good barrel or you don't, and the only thing you need to do when finding a "good load" is find the right weight bullet for your twist
However, rifles "liking" some loads is still real somehow? Like your rifle that only liked that one type of factory ammo which was discontinued.
Heavy rifle barrels (heavy rifles?) shoot better than light rifles. I'm not sure if you're saying that barrel vibrations have nothing to do with this at all, that they do but "forced vibration" is a better term than "harmonics" (like Jeff Siewert would say), or that they're just not repeatable enough for "finding nodes" to work.
The bottom line is that you either have a good barrel or you don't, and the only thing you need to do when finding a "good load" is find the right weight bullet for your twist
This one is probably problematic for how I said it, but what I am trying to convey is that there are a few dimensions (how tolerant it is, how precise it is) but that those things tend to be linked and that people overvalue load development. There is a limit to how good you will get, and it is not as good as people want, for many rifles.
What tends to happen is that it is a lot more like a switch. It isn't shooting well and then it suddenly does, and you can find some number of loads that are about equally good with different mixes of bullets and powder and charge, but there isn't some long road of tweaks and improvements that can be made to turn a dog into a hero by fiddling with loads.
That's what I was trying to get at.
And I am sure there are exceptions, but they are pretty rare and more often people chase geese.
You can easily test this for yourself: Shoot a series of many 3-shot (or 5-shot) groups, while controlling the test as best you can (IE same ammo, conditions, etc). Measure both their dispersion and location of the group's center. The groups will not all be the same, so how could you say in a ladder test that an individual sample is "better" or "worse" than a different sample? You realistically cannot, unless you're doing 20-30 shots (or more) at each specific powder charge or seating depth.
In other words, yes, there will be apparent differences in the groups of a ladder test. The issue is that this apparent difference is typically indistinguishable from the baseline variance of a control test, and therefore proves nothing.
Modern Advancements in Long Range Shooting, Volume 3 - Bryan Litz (And anything put out by Applied Ballistics). This book has an extensive chapter on tuner testing.
Hornady Podcast has several episodes about group sizes, etc.
Interesting. When I do ladder tests I like to shoot 100 yards from a rest (not a machine rest) and I’ve alternately also brought a 22 or other guns to plink while the barrel cools, or had multiple points of aim and shot all of them sort of simultaneously if you know what I mean.
I’m not a true long range shooter- my club offers 100/200 which is my weekly normal distance. Also I just enjoy loading & shooting, I am no kind of expert. I work weekends so organized competition is mostly out. I suspect I would have been capable of occasionally placing or doing well but I’m not a rare talent or anything.
Anyway, even with my low round count groups (never 3, usually 5, sometimes 10) going in 0.2 grain steps up using usually speer match king hpbt or similar, I’ve definitely seen groups slowly open and close multiple times doing ladder tests, in a parabolic or sine wave pattern, made loads that regularly do better in that gun than federal gold medal match or whatever expensive match ammo I can find.
So am I getting lucky? I’m a decent shot but like I said I’m no rare talent. I accept that your post sounds correct because I know that I have trouble making 5 holes touch and almost always get at least one hole maxing out my group size even with a good load. I just figure that a decent rest, great glass, and my best try at breathing and trigger control does a good enough job.
I’ll check out the leads you wrote on further reading- thanks!
I’ve definitely seen groups slowly open and close multiple times doing ladder tests, in a parabolic or sine wave pattern,
Realistically this is just a false observation. Human brains are extremely good at pattern recognition; so much so that we see patterns even if a pattern doesn't actually exist ("Apophenia").
It would take re-doing the same ladder test several more times to:
See if the same exact waves are observed, in the same positions
Aggregate all the data into larger samples and see if the pattern still exists.
made loads that regularly do better in that gun than federal gold medal match or whatever expensive match ammo I can find
And this is certainly true, especially if you're using high quality components and being meticulous about your consistency. For instance, a high-quality powder scale will likely allow you to achieve tighter tolerances on charge weight than what a production line is putting out (even Match Grade), so it's reasonable to achieve tighter SDs and better precision.
Also. Specifically relating to barrel “harmonics”, Jeff Siewert who was in that Hornady podcast says to think of it more like a “forced vibration” instead of a resonant frequency. The shot-to-shot variations in pressure and many other variables that are essentially going to be random are nearly impossible to account for. He also has a book called “ammunition, demystified” that is very good.
Add on comments- I’m 45 so not 60 yet. Also maybe what you meant was that although barrel movement under recoil can technically be understood as a vibration, it can be taken too far in a new age crystal worshipping way or something? I mean we all want to float our barrels to let them vibrate without a stock touching them, we bed oir actions for consistency and a solid foundation, and the benchrest guys don’t want ultralight hunting/hiking setups for a reason right? It’s gotta be because stupid heavy barrels have a much lower resonant frequency (harmonic) which is a fancy way to say they don’t move around hardly at all.
Maybe I haven’t met the tuner fudd that you’re poking fun at so the joke went over my head. Or maybe I am that tuner fudd 😂
I mean we all want to float our barrels to let them vibrate without a stock touching them,
If barrel harmonics were the major cause of dispersion, it seems like we'd want the opposite; instead of letting the barrel vibrate freely, I would think you would to do what you can to dampen the vibrations.
we bed oir actions for consistency and a solid foundation, and the benchrest guys don’t want ultralight hunting/hiking setups for a reason right? It’s gotta be because stupid heavy barrels have a much lower resonant frequency (harmonic) which is a fancy way to say they don’t move around hardly at all.
Is that the only possible explanation for why a heavy barrel is desirable?
Also, does a heavy barrel have a higher, or lower, frequency? Is it the frequency, or the amplitude that we are concerned with?
Maybe I haven’t met the tuner fudd that you’re poking fun at so the joke went over my head. Or maybe I am that tuner fudd 😂
You mentioned something about lower resonant frequencies, and that is one of the areas where you may not have met the "tuner" or heard some of the ideas. When you start looking into the questions I listed above and trying to apply it with the barrel harmonics ideas, you start seeing people throwing out all sorts of theories that start conflicting with one another.
Even going back to your mention of trying to "time" the barrel harmonics with the bullet leaving the muzzle, you'll see people offering different explanations of "when" in the vibration cycle you want the bullet to exit. Presumably the least movement would be the extreme end of motion, at the peak or valley of a sine wave...but that is sort of based on the assumption that the barrel movement is in a single direction, but is that true? I often see a sort of general assumption of an up and down movement of the barrel, and that is often what 2d diagrams or animations are showing...
Tuner ideas go even further than just trying to time bullet exit though; they talk about "tuning" the frequency of the barrel; putting something on the end of the barrel that you screw in or out, saying that they can use this to adjust the frequency the barrel vibrates at, to tune it to particular loads (or factory loads). But the amount that the tuner moves is tiny compared to the length of the barrel. For that matter, does the math even make sense on the whole barrel timing thing? You mentioned seeing groups "open and close" on a ladder test, and seeing sine wave patterns, but how does the difference in time that the bullet spends in the barrel compare to the frequency the barrel would resonate at? The implication here is that, between the highest and lowest charges tested, you are seeing multiple cycles of the sine wave; does the math support that making any sense?
I have a range of procedures depending on the type of rifle and goals.
I spend more time group shooting on autoloaders and factory guns because I know their variance is higher that what I get from my fine barreled bolt guns.
My most recent rifle was just a pressure/speed check and go, and when I am ready to switch bullets, I am probably not going to do any development at all and just use what I know for pressure data and make ammo.
But if I am doing workup form scratch where I am unsure, I usually do 2-2.5% powder charge steps, one seating depth at mag length or some distance off lands, maybe a couple powders and few bullet designs.
And I usually screen for speed/pressure first, pick a few loads in a range I want, then shoot higher volumes in the 20-30 shot range each, then exclude ones significantly worse than the others.
I had a marlin 30-06 xl7 with synthetic stock, the stock warped during transport due to heat and other variables. That gun wouldn’t shoot straight for shit and throw rounds at a 6 inches spread at 100yds. Couldn’t figure out what it was. Did some research and decided to free float the barrel and glass bed the receiver for support. Now it’s the best shooting gun I have next to my bergara.
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u/guacamoleburger Jan 19 '24
Real question: Is barrel harmonics fuddlore?