I was just watching the Bowhunter TV show and they did a tip segment with Randy Ulmer. I always He was describing how he determines whether an arrow should have a Right Helical or Left but marking the arrow with a sharpie and shooting 2-3 yards. He determined that the bare shaft had a counter clockwise or left natural rotation so then he used a left wing helical.
In all my years of arrow tuning I have never heard of this. Seems brilliant. Have I been living in a cave and is this is well know thing?
I had done it when shooting my recurves and then got away from checking when I switched back to a wheel bow. Ranch Fairy on YouTube and his arrow tuning videos got me to really look at my arrow set up. Nock tuning sounded crazy, but it seriously made a huge difference in how a bare shaft flies and impacts the target. Once I figured out my Prime throws arrows out with left rotation, I fletched that way and went with left single bevel Cutthroats. They group right along my field tips out to 50...
I am no expert but guessing you did not live in a cave. I did not watch it but was it fixed blade hunting arrows? I do not understand why it would happen or what would cause it. If I did likely it still falls under irrelevant category for me. I hope and do learn some new every day.
I was always told the string twist determined what way it naturally spins. I fletch my arrows to match the twist. Doubt it really makes a huge difference for a non expert like myself. But I figure it can’t hurt anything.
If the arrow naturally wants to spin one way makes sense to fletch that way. But after testing I don’t see that big of a difference in accuracy. But my thoughts are that it doesn’t hurt and can only help with accuracy.
And yea it’s the twist of the string. Majority of string makers twist a certain way and arrows want to Rotate left..
I prefer right spin thou as points don’t loosen as well as Some broadheads have right offset
Makes sense, like about anything Randy says when it comes to archery or killing big muleys. More than I care to care about but I'm also currently shooting arrows with right wing feathers fletched with a left wing clamp so obviously a whole lot of small detail gear tinkering never makes it on my "to do" list. :^)
These type of details are why Randy and Levi are as good as they are. They do sweat the tiny little details that all add up to a little more accuracy. Trying to remove everything but human error from the set up.
Also for many, It’s these kind of things that make archery challenging and fun. Always learning and always tweaking a little bit. But let’s face it, not everyone has the time, and their arrows fly good enough for them.
Levi and Randy shoot like they do because they have an incredible talent.
If I were competing on a level that missing one shot by 1/64" over the course of a season could cost me tens of thousands of dollars, I would sweat these kind of details. For a hunter, it's way too anal.
I somewhat agree with it being a bit over the top for a hunter, but I would say I like the idea of it being fletched properly to match natural spin so that it starts rotating quicker and doesn't have to fight the opposite spin for the first few feet of flight. Just makes sense in my brain to start it correctly, getting it spinning faster and should help stabilize flight better. Just my .02 thought!
X-man nailed it! Where’s Trax and the boys when we need them....
Back to the topic. I read this a few years ago, tried it and found the arrow spun the opposite direction of my fletched shafts of which I have 100’s. So I decided it wasn’t for me and moved on thinking I’d try it next time I built more arrows.
I also thing GG’s post about the cumulative effect of Ulmer’s tech tips is spot on.
During the power stroke, the helical or offset vanes are being "loaded" because the nock won't allow it to turn. As soon as the nock clears the string those vanes will "unload" that tension and apply it to the shaft. Is that enough to overcome any very slight tendency to counter rotate? I don't know, but if there is no (perceivable) accuracy advantage, then why incur the disadvantage of a counter clockwise spinning shaft?
IF string twist is responsible for bare shafts wanting to rotate in a counterclockwise direction, even though it is quickly "overcome" by the helical of the fletchings, why wouldn't string manufacturers have chosen the opposite twist? Granted, it is practically a negligible effect, but since a clockwise shaft rotation would tighten the arrow tips, why not take advantage of the effect? What advantage did string makers see in chosing the opposite direction of twist?
I still have a hell of a time buying into the notion....
Stop and consider that arrows are basically manufactured by the mile to some pretty exact tolerances for mass and straightness, and somehow we are to believe that cutting that miles-long arrow into 2 1/2 foot lengths yields pieces which will “naturally” rotate in one direction or the other, seemingly at random.
And does this happen with aluminum as well as carbon? With wood, I can almost see it being a possibility. With carbons, maybe the spiral wrapping process is a factor, but why would that vary? Is it that some get swapped end-for-end somewhere? Where is that a non-issue because clockwise is clockwise from one end or the other? (I’m trying to visualize that and I am drawing a blank at the moment…).
It would definitely be beyond my shooting ability to see a difference from this... That said, How is he figuring rotation with the sharpie? Meaning, how do you know it's spinning left or right? High speed video?
Medicineman- I asked a string maker once. It’s easier to build strings a certain direction and most string makers do it that way. The way they do it makes my arrows want to rotate left. Not exactly sure why they all do it that one way?” Thou?
He said he could build the strings opposite resulting in the arrow spinning right. But it would have to be a special request.
As far as finding out which way. It’s easy . Just have a mark in the shaft and shoot it at 1 foot and then 3 feet. You will see which way it’s starting to spin
So some are saying it's the shaft and some are saying it's the bow (string) that determines the natural rotation. If the same bow shoots all shafts the same rotation, then it's the bow. But some are saying that they shoot all their shafts bare and then fletch according to how they rotate from the same bow. So then the question is, which is it. If one can test enough to say it conclusively does have a natural rotation, then it should be easy enough to isolate it to one or the other.
Now two questions from that demo. If the string was twisted opposite but the serving was wound on the same, would the results differ? That is; it’s the serving not the string?
And second: if you shot the string that rotated shafts counterclockwise with right hand helical, would it still rotate counterclockwise in those same distances. And if so, how much distance before it corrects to the fletching direction.
Good question, Rod. Since serving should always be twisted in the opposite direction of the string, I think the general rule applies. The bare shaft will always rotate in the direction of the serving. Now, whether it's the serving or the string that causes that result, I can't say. But the results are real based on my testing.
The fletching direction will always overcome the small amount of rotation that the string/serving causes on the bare shafts. I think Randy's point is, if you fletch in the same direction the bare shafts rotate, the fetching and string/cable are working itogrther, not opposite of each other.
I know this is anal minutia to some, but I enjoy this type of tinkering. Does it make me a better shot? Who knows. But, If I think it helps, then it probably does at some level, even if it's just in my confidence.
I consider what Randy says as pretty darn close to gospel, but unfortunately I don't think I'll ever been good enough at shooting to make this little tweak matter. I saw it years ago, decided it might make a miniscule difference at long, long distance, and moved on because I was sure I wasn't good enough for it to matter. Honestly, this may provide confidence more than it does an actual physics-based advantage (a meaningful one, that is).
To me it goes into the same category as a June Bug hitting the windshield of a truck doing sixty mph. You could calculate how much it slowed you down, but you couldn't physically tell it happened nor measure it at the gas pump.
In the end, I want all my arrows spinning clockwise and that's what they're gonna do. Too many other things to spend time on that can make a difference.
So in theory, you figure an arrow's desired rotation, and your fletch marry to that direction, thus the arrow stabilizes easier and you have better accuracy.
This makes sense, but I'm very confident that even if I did it, my skills are not good enough to see a difference. Ill probably try though, because, frankly, that's a pretty cool tidbit I've never thought of before and playing with it would be interesting.
Would love to see someone with a Hooter Shooter test a dozen BH-tipped arrows, six fletched RH and six fletched LH. Shoot at 50 yards and see how each groups. That should settle the issue scientifically.
GF the rate of spin is directly proportional to the number of twists in the bowstring multiplied by the square root of the strand count in the string but you need to divide that by .76 it Bcy string material is used
A lot of people can't see the difference in trying this. Yet year after year some of the same guys can't get fixed broadheads to shoot straight and move to crappy mechanicals as a fix. Perhaps it these small things like nock tuning, arrow rotation ect that make a bigger difference than one thinks. I know for me personally I'm starting the process of putting together my arrow building bench. I'm interested to see if I can tell if arrow weight, foc and spin make any difference for my shooting. I do a lot of spot and stalk hunting for elk and deer hopefully a speed goat year next year, where I may want to take that 60 yard shot with confidence. If your just shooting 20 yards at deer from a stand it probably doesn't make much difference.
Ambush Not sure why you take that personal ?? Was the really the fact you'd rather dismiss something that would require a little more time or effort that could enhance your skills?? We do owe it the animals we hunt to be as proficient as possible. To be fair it's always the guys that put in the least effort and complain that their broadheads don't tune. Mechanicals are crappy
“ Was the really the fact you'd rather dismiss something that would require a little more time or effort that could enhance your skills?? We do owe it the animals we hunt to be as proficient as possible. ”
So what about becoming proficient enough at actually HUNTING to get yourself into close range instead of lobbing shots from 60 yards?
Seems we all expect other people to work harder at we work at ourselves.
I still have yet to see one good explanation of the whys and wherefores of this so-called “natural“ rotation. SOMETHING has to cause it, or it can only happen through direct violation of laws of Physics. And I’m not betting on that.
JMO, put your time and energy into your shooting however makes you the most confident in your abilities.
Then hunt like you’re only good to about 10 yards.
People who take shots at animals knowing that they are pushing their own limits really chap me.
GF I practice out to 100 yards all as do many on here. "I wouldn't shoot an animal past 60" doesn't mean I do. In over 35 deer everyone of them has been 3 yards to 20 yards all have been spot and stalk public hunting in the western plains of Kansas "no trees". My longest shot was a heart shot elk at 50 yards. Maybe someday you can show me how's it done, in all seriousness I do everything I can to be a better hunter every year, if you can teach me something new then teach. In the mean time if you do western hunts you need to be as proficient as possible with fixed broadheads. I haven't played with the left - right fletch yet. I do intend to at least see if it makes a difference when I put together a new set up this spring. Don't be lazy, push the limit you're comfortable with and you'll be a better hunter at 10 yards. Totally expecting the speed goat shot to be 30 to 40 yards. Not everyone hunts over feeders my friend.
Only the 1 percenters in terms of shooting would ever be able to tell a discernible difference, if there is one. Ulmer is definitely one of those. While I shoot ok I am nowhere in the league of the elite. I can't tell a difference.
How would the twist of the string cause a bare shaft arrow to develop rotation one way or the other? They would be rotating at 90*of each other and the string should not be tight enough in the knock to influence it. I'm not buying that for a second.
So, how do explain the very repeatable and consistent results of the video I posted earlier in this thread? True bow technicians, like Randy Ulmer, don't just make this stuff up. It's based on countless hours of testing and thousands of arrows shot.
When I was a sponsored 3D shooter, I noticed there were generally 2 types of shooters. The first type was the "close enough" guys. They'd rely on the shop to make their arrows and tune their bows for them, and they were reluctant to tinker or experiment with anything out of fear of messy something up. The second type was the guys who were always tinkering with or fine tuning something, trying to improve their setup and their shooting. Any guess which type guys usually won the tournaments?
Anyway, instead of dismissing something you have no experience with, why don't you go out and actually test it for yourself. You might be surprised at the results.
Bare shaft rotation depends on whether you are above or below the equator. You have to remember that when you go to New Zealand. Need a set of reverse fletched arrows for those southern hemisphere hunts.
So what you’re saying, Wally, is that only an elitist SOB would dare challenge another hunter to just get closer, but you’re willing to sweat “natural arrow rotation” and challenge another hunter on his dedication to his Craft because you’re Superior in some NON-elitist, NON-SOB kind of a way???
Not buyin’ that, either.
@Matt - “ So, how do explain the very repeatable and consistent results of the video I posted earlier in this thread? ”
Better question is, how do THEY explain it? If it IS happening, it MUST be happening for reasons explicable by the laws of Physics. I just wanna hear it.
“ The second type was the guys who were always tinkering with or fine tuning something, trying to improve their setup and their shooting. Any guess which type guys usually won the tournaments?” I don’t think a lot people spend more time thinking about or experimenting with their set-ups or working on their shooting than I do. Not people who don’t get paid to shoot, anyway. But I’m not blaming my gear for those “fliers” - pretty sure they’re all on me. It’s not my arrow rotation that’s keeping me off o’ the podium.
That said..... I’ll be the first to agree that anything that makes you BELIEVE you are better... usually does. 90% of this stuff is half mental, right? Meanwhile, I’m just asking what causes this phenomenon to occur. And I reserve the right to not believe in that which cannot be explained by science. This ain’t religion.
I really don’t give a rats ass if you believe it or not, GF. Something that’s so simple to test yourself doesn’t need a scientific explanation. Its real regardless of whether you can wrap your little brain around it or not.
I took the time to do this just recently, didn't take much work. Then fletched according to the rotation. It might not make that much of a difference for me as an average shooter, but then again why not.
Like toilets..... this works better if you're in the southern hemisphere.....
First.... I'm not gonna do it simply because a left heli has a tendency to unscrew your broadheads on impact. Not an issue if you're gluing them on, but the vast majority in archery today say "screw that!"....
Ask me how I know.... in the days of old when I shot feathers you could get GREAT sales at times on left feathers. And I'm a cheapskate. For a time, left it was....
Secondly..... is anyone aware of how tiny a fraction of energy it takes to turn a bare shaft in mid air? It would take some sophisticated machines to come up with how much was being imparted, much less what was needed to overcome such a tiny amount with the fletching. Be like separating the fly crap out of the pepper shaker.....
I'd say Ambush was spot on. The preload laying over the fletch at launch before the arrow ever left the string would be magnitudes more and overwhelm any energy imparted from string twist (or asymmetric spine, I've heard both) that might effect it literally like it wasn't there. Likely need even more sophisticated equipment to measure any difference it made..... if any could even be measured. Well, unless of course you shot it out of a WB......
Like I said above.... screw that..... but then this is from a guy who's sock drawer is completely disorganized....
Can’t say whether it makes a difference or not. Don’t care to find out. If I were a world-class archer where 1/16” could cost me thousands of dollars...sure. Worse case, if it makes a 2” difference on an animal at 40 yds, once again, don’t care. If it makes you more confident, great. For me? No thanks.
There is NEVER more force being applied (by the fletching) to rotate an arrow than there is at the instant at which the nock leaves the string, and prior to that the shaft is prevented from rotating (either direction) by the nock being clipped into the serving.
Like I said before; if you believe it’ll make you more accurate, it probably will - for at least a coupla weeks. But overall, it sounds an awful lot like micromanaging the meaningless microminutiae in the belief that it somehow gives you control over it or makes you superior to those who don’t.... when in fact it’s just a distraction from what actually matters.
All of this talk of arrow rotation direction is as ridiculous as some people floating arrow shafts to determine spine, or aligning broadhead blades with vanes. I would venture to say that an extremely low percentage of people who shoot arrows can shoot well enough to notice. Archery folks are well known for their willingness to buy into "false doctrines " and other foolish notions. And by the way, string twist direction cannot possibly have any effect on arrow rotation, in EITHER direction. The two are in different planes.....by a factor of 90 degrees. One having any effect on the other is entirely impossible. THINK about it, folks!
Has anybody tried shooting the exact same shaft from the same bow while alternating between wearing a Trump T-shirt and a Biden T-shirt? Left and right. And yes, I know you'll have to shower right away before you can post the results.
I've never heard of bare shafts rotating, but if the rotation is arbitrary because each shaft has it's own preference, due to inherent weight balance, wouldn't that produce a quiver of fletched arrows of both rotations? Hmmmmm
Yeah, I was thinking that. Then again, instead of altering your arrow building gear and buying fletching of the opposite rotation, why not just change the string to one of the opposite twist? That is easier done if you normally build your own, I get that.
"And by the way, string twist direction cannot possibly have any effect on arrow rotation, in EITHER direction. The two are in different planes.....by a factor of 90 degrees. One having any effect on the other is entirely impossible. THINK about it, folks!"
It also implies that your string is unwinding on release which is what presumably is causing the rotation. still not sure how that would cause the arrow to rotate as the longitudinal axis of the string and arrow shaft are at 90* from each other. Knowing the science behind it could confirm the theory or dispel the myth.
I saw the Randy Ulmer TV spot where he explained this issue. I have a lot of respect for him and his archery accomplishments. But sometimes I wonder if these personalities need to “ make an issue” so they can have a two minute TV spot. If doing this adds a tiny bit of accuracy, I’m not good enough to gain that accuracy.
I find it funny that there are still folks who believe this nonsense. Most people of average and up intelligence should not have to ponder this for very long.
I think we all know that the arrow begins slowing down the very nano-instant it leaves the string. That in itself should be all you need to know for this subject. The fletching never has more drag than it does at the exact moment it leaves the string. There is no magical "counterforce" to overcome other than torque induced by your hand, cable guard and/or cam lean. That torque is what might influence a bare shaft, not the string twist.....or serving ..... Put fletching on and that bare shaft rotation is easily overcome before the shaft leaves the string. "Come on man"
Randy literally gets paid to come up with tech articles. He is a very talented shooter. He could outshoot most of you with a 40 year old bow. That does not however make him a qualified mechanical engineer. "Fake News" (insert meme of sheep following each other off a cliff)
It's probably not a noticeable benefit for most of us, but the rotation part isn't fake. Even a fletched arrow can come out of the bow and be spinning opposite the direction of the helical before it begins spinning the other way (i.e. right helical fletch but coming off the bow spinning left initially). It's just a matter of how much it does or doesn't make a difference for the person behind the bow. I did it only because I had to fletch arrows and it took less than five minutes to test it, but it almost certainly won't help me all that much. Ha! It's easy enough to do so I figured why not.
I shot it into a target at a few feet, both fletched and bare shaft to check both. My old arrows fletched with right helical also coming out of the bow rotating left. You are correct I did not test at what point it then reversed it's direction. They were coming out left and with a right helical should then spin right. I am sure that has been tested by those with slow motion cameras, but I just tested the initial rotation and fletched to that.
Pretty cool video! I had bare shafts turning at a fast rate, meaning closer distance and more rotation. Arrow makeup probably has an impact I'd guess. The Paige Pierce video she did with two different arrow types out of the same bow was very interesting. But as you said, probably like picking fly poop out of chili. Pretty minimal for me in terms of overall gains. :)
“ Even a fletched arrow can come out of the bow and be spinning opposite the direction of the helical before it begins spinning the other way (i.e. right helical fletch but coming off the bow spinning left initially). ”
I’ll buy that when I see high-speed camera footage of an arrow with 3 different colors of fletching. If this “natural rotation” were strong enough to overcome the influence of fletchings, we wouldn’t need fletchings AT ALL in the first place.
Seeing is believing.... but not understanding what you saw can lead you to believe in some pretty wacky stuff...
Haha! GF you make a fair point. I just wonder if I shoot a right helical arrow that naturally does rotate left, does it only spin left the entire time until impact? The right helical would want to try to counteract I'd think. I think others have tested, but I don't have a video for you. :) For me it's really just tinkering and interest, I do not think it makes me any more accurate (but better archers it may).
Interesting, Kurt! Thanks. This is the one I mentioned from Paige Pierce, I think I've seen on this forum before as well: https://youtu.be/ebSxqxBq1w8 Credit above to WapitiBob who already shared here. ha!
BB's comments have made us all smarter. It's all fake news. Just make sure your bow is sighted a few days before season and throw on a crappy mechanical. If you do this you'll as good as you can ever be. Laziest comments I've ever read from bow hunters. Practice and tinker all year, tune your bow tune your arrows ect, 'only takes a few minutes through the year. Make sure you are shooting your best even if it's 1/16th of and inch. That 1/16 could be 6 inches in the field when adding other variables. Oh wait that's the broadheads fault. Good Luck in 2021 to all I'm out
“A fletched arrow came off the bow spinning in one direction and then reversed direction to spin the other way? How did you determine that?”
As I mentioned the last time this came up, it takes all of two minutes to see a fletched arrow come out of the bow spinning one way, then reversing when the fletch takes over. My hyper speeds reversed at about 10 feet.
And anybody that wants to hit what they’re aiming at has some offset.
Shoot a bareshaft into a target butt at 3' then 6' and you'll see the rotation. if you're skeptical, shoot into different target butt media. I've done it with 3 types of target butts. Then do the same with an arrow that's fletched opposite the bare shaft rotation. As you move back and shoot you'll see the rotation stop then reverse. As I've said 100 times, so far it makes zero difference on your score card at the end of the day. When Mike Schlosser says he can see a difference I'll worry about it. Till then, it's just another archery "thing" people get twisted up over.
World Archery does some super slow motion videos and they had one where you could see Stephan Hansons arrow reverse. I have not seen it but Gillentien talked about it on a padcast of his. Kaminski has a youtube on it too. Their vids can be pretty good. I saw one of Reo Wilde where you could see his front bar oscilating at the shot while the bow and the bars front weight never moved; perfect sine wave
Again, just for everyone to get it straight... The string twists and/or serving have nothing to do with this.
Your bowstring as viewed from behind in super slo-mo will show your string either going forward at the release like "/" or "\" or "I". Which one of those orientations is dependent on a couple factors. Hand torque, natural bow torque from cable side-load, limb twist/cam lean, and right handed/left handed bow. Obviously we all tune our bows to achieve as close to the "I" as we can. However, if your string does "\" as it goes forward, the bare shaft will rotate counter-clockwise. If your string goes "/" your arrow will rotate clockwise. It's not rocket science guys.
I agree that String/serving twist has no influence on the bare shaft rotation. I'm surprised however that there was measurable rotation change with a fletched arrow at all. I would have expected the fletch to take over immediately if not sooner.
Some bows yes. I have had bows that have had near perfect vertical string at the time the arrow is released. In those cases, I could change the bare shaft rotation with my grip..in theory. I had a Martin Scepter 20 years ago with a shoot-through cable system that we shot through paper at all yardages out to 20. That bow shot bare shafted 2613's without a single bit of rotation all the way to 20 yards. I then fletched those shafts with 2 RW feathers and opposing 2 LW feathers in a 4x90 orientation just to prove a point that drag was more important than spin with regard to arrow stabilization. I went on to shoot regular 300's with mid 50's x counts with that bow. Regularly beating the "ArcheryTalk" experts who would rather believe the internet posters on AT than to listen to science and reason.
Thank you, X-man. That was a much better explanation than I could come up with.
The first time I saw slow-mo video of it, I was shocked to see how much lateral motion there was in the string and cables. Sometimes the string whips back and forth in a snake like motion. There's no doubt that most typical compound bows put a slight rotational force on the arrow, inherently. Grip torque can compound it, or counteract it.
The straightest nock travel I've ever seen was from a bow with a "shoot-thru" cable and riser design. I've often wondered why that concept never really caught on.
Shoot thru's never took off because marketing can’t sell a hunting bow that loads an arrow between the cables. I developed the first shoot thru system before I went to work at golden eagle in the early 80’s and marketing kicked it loose half way thru the patent process. Jim Despart built a similar system about 10 years later and sold it to Martin and they ran into the same problem.
Similar to this arrow rotation, I sent that system to the #1 shooter in the world for his review. His reply was "Yep, it does exactly what you say it does but it doesn't make a point worth of difference after a day of shooting." And that holds true today. People get wrapped around the axle about things that really don't matter; cam lean and lateral nock travel are nothing but a time suck for people that should be spending their time on the range shooting arrows.
Why do you think nocking an arrow thru the cables was such a marketing stumbling block? One day of shooting doesn't seem like enough time to form an objective opinion, even from a top tier archer. The shoot-thru design I witnessed perform out of a shooting machine was noticeably more accurate than a conventional side-cabled bow. We're talking fractions of inch at 20 yards, but that can often be the difference in spot shooting, as you know.
At the time, hunting bows were 90% of our sales and with virtually everyone loading an arrow point first, marketing saw no way to convince hunters it would work. Martin used Departs design on their target bow and even then they couldn’t get traction.
I found this thread to be very educational. I do have a few thoughts. Fletching stabilize an arrow by drag and rotation. Drag causes an arrow to straighten by pushing the fletching to the back and rotation by changing the influence of arrow imperfections. If an arrow is rotating CCW initially with a right wing fletch I would think that that would increase the drag on the fletching until the rotation is reverse. The increased drag would come exactly when it is needed to straighten out the arrow flight caused by torque, timing, tuning, and deflection. Once the arrow flight has recovered from the initial shot by the drag the arrow is now rotating which will help negate the impact of arrow imperfections. I could argue that it is better to have the initial rotation opposite that of the fletching because it would result in an increase in the initial drag when it is needed the most. I doubt that it matters though.
“I figure I'm just a not a good enough natural archer not to. Can’t hurt.... Right?”
If the phenomenon is real, it might even help. If there IS no such effect, it can’t possibly hurt anything.
It would be kind of interesting to hand a bunch of top shooters a half-dozen arrows each, with an unspecified number of each half dozen fletched “correctly” and the others “backwards”, and keep score at the arrow ID level throughout a tournament’s worth of shots, then determine whether there was any difference in the scores for one bunch or the other. Just have to make sure that nobody - neither judges nor shooters - has any way of knowing which arrows are which until the shooting is over. Maybe a microchip glued inside the nock or something....
But it still doesn’t stand to reason that there is “something” causing an arrow to rotate which is powerful enough to overcome the influence of the fletching at the instant of nock-string separation (when the fletchings exert the greatest force) and then that “natural” rotation is overcome over time & distance by ever-diminishing force applied by the fletching.... If this Mystery Force is strong enough to “win” initially, what changes??
At the very least, it suggests that the rotational impulse is applied while the nock is on (or undergoing separation from) the string.
I have a bit of a hypothesis on this, but it would pretty much blow up if this same “effect” were to be seen in aluminum....