Getting Technical With Barrel Twist Ratios - Pellet Stability & Env. Variables

I am going to venture into this minefield and try to cut a path to a safe spot because I want to save this very interesting topic. I posted a couple of questions in the recent past about airgun accuracy (see below) and this topic is of great interest to me: 

www.airgunnation.com/topic/what-makes-a-pcp-consistent-and-accurate/
www.airgunnation.com/topic/airgun-accuracy-factors-follow-on-questions/

I was following this current thread with great interest and I tried to understand the relevant posts and data presented. Even as the argument ensued, I tried to leave the emotional parts out of the reading by skipping to the parts that added value and understanding, i.e. the link to the Pyramydair study by Tom Gaylord, and the comments by TDK, Alan, and Bent...all of which had some great observations. Then after reading all these auxiliary information I returned to what Harry posted and AZ's comments. And Harry's concern as far as the accuracy of the test performed by Tom Gaylord, which (for me) seems valid. I do not have a Talon but 1-2" accuracy at 25 yards and 2-3" accuracy at 50 yards are suspect to me as well. I do not think Harry meant to imply that Tom Gaylord presented false data. It's just the data really seems to be so far from norm for such mainstream PCP rifle (based on my experience at least) that surely there must have been some additional factors, The word "spurious" (which I had to look up in the dictionary) in this case pointed to the usefulness of the "comparisons" derived from such results, and not to the work or the integrity of Tom Gaylord himself. I also found such groupings strange and was also hard to see much of any patterns from which to make conclusions, which was contrary to the very excellent and useful "velocity table" test that Tom Gaylord conducted first. Another thing I also noted, and so did Alan, that the barrels were not all choked, so that is certainly a factor in itself which could make or break such a comparison when you trying to compare apples to apples. Again, I am not an expert, and would welcome any corrections to my understanding of this. 

I've been reading Harry's comments on another forum for a few years, and also here at AGN which I joined just a few months ago. I am not new to airgunning, but I am certainly not at a level like many who post here with authority and looked upon with respect. However, with time and some effort I can understand most of the complex concepts if well explained, well presented, and backed up with empirical or repeatable facts. Turning to Harry's posts: I may not understand all, but the ones I do I can follow the logic and understand how he comes to that conclusion. I have not yet detected any malice or misleading information which would have made me not trust him, nor did I discover any information he posted that I discovered as being wrong. Again, I am not an expert and I may not see some errors, but Harry does post his work and in great details on this and other forums and those posts are open for review, criticism, and correction, etc. As they should be, because from such discussions, debates, and occasional mistakes we all can learn. 

AZ, as I mentioned, I am new here on AGN. You have +16 accuracy points, so that tells me that you know what you are talking about. Thus I read your posts with respect and I assign a higher degree of credence to them. But since I am new here I cannot evaluate you work and your knowledge that you passed on here and potentially at other forums. I am interested to know about your expertise and background. This is not a challenge, but a genuine interest. As a matter of fact I was leaning towards dismissing your comments until I read your post about "...if somebody knew why 570-585 was established as the velocity (ISSF) and why this velocity is very accurate...." . I am actually interested to know. Also peaked my interest that your background is connected to 30 years of gun manufacturing R&D. I think most airgun enthusiasts would love to be able to use a real high-tech R&D facility/setup to experiment and test their rigs. We spend weeks tweaking and testing our rifles with hundreds and thousands of pellets, and I myself seem to walk away after each occasion with more new questions than answers. So, I think that with your background/expertise this thread could be really helpful to the rest of us if not bogged down with this personal back and forth. Maybe you can PM me if you so choose.

Just one more comment about the forum moderator's work. Albeit I would also fight until the last minute if I think I am right, I do believe (for whatever it's worth to you, AZ) that it was a misunderstanding to think that Tom Gaylord or his work was disparaged. Instead, one may say that the conclusions he arrived at may be "misleading". I would also flag those groups, especially after such logical results which were presented in the first velocity table. I clearly would not assign the meaning "fake" or "fraudulent" to his tests (and I doubt that Harry did either). I think it's fair to say that something needed more looking into. I cannot speak for the moderator, but I believe that his respect for your prior contributions to this forum tempered his actions that otherwise would have led to a very different outcome for most other forum members. 

Thank you fe7565. You and many others have obviously been able to read my simple statement easily - poor groups from which sound support for an hypothesis is lacking. No personal "attacks" on the integrity of US institutions or individuals (Tom); no inference of faked data. But the results could only be inconclusive, for the reasons some of which others have pointed out; and I'll bet Tom probably feels the same.

Further to AZ's personal vendetta :- above he has implied I somehow discredited, crashed and ridiculed some contribution he feels he has made .
AZ wrote that: 'He (ie., me) posted ” Don’t get hang (sic) up with Barrel Twist Ratios” discrediting and crashing what I was trying to get members to know in a ridiculing way'
If anyone can genuinely point out where I have supposedly discredited AZ, crashed or ridiculed or abused him anywhere in the whole thread he refers to (below), I will make a public apology. I am fed up with being deliberately misquoted and inaccurately paraphrased with a view to putting my integrity into question before others, using libel and slander, and his snide references to my age. ... Wouldn't you be?

If it doesn't show the Topic is near the bottom of page 3 General Airgunning
/topic/current-barrel-twist-rate-reality-dont-get-hung-up/#post-41837

As for his mention of Bill Calfee, I haven't the least idea what AZ is on about - I have never made a negative comment about the man or his rifle work. Some of my friends, who do know him, highly regard Bill's expertise.

Michael has been more than fair and tolerant with AZ who should forget the personal agenda, sign off openly on his own work, as I have done; and let his views and research stand up to the same scrutiny that mine have survived internationally these last 14 years. ......... Regards to all, Harry.

@Yrrah: well said!

I also asked if somebody knew why 570-585 was established as the velocity (ISSF) and why this velocity is very accurate?

I've never heard about this, and decided to do a bit of research. I find that Dr. Beeman has researched this as well, and covered the subject in several white papers. However, when I looked around the ISSF (International Shooting Sports Federation), I could find no mention of this specific range of velocity. But what I did find was references to spring-type airguns, in .177 caliber (the most popular caliber up to about circa 1985, and still the ISSF's official caliber), and their average velocity falls within this range. And no argument that these guns are very accurate out to about 15 yards. Past that, not so much.

In one of Dr. Beeman's white papers, he speaks of accuracy as a combination of factors—twist ratio, pellet BC, pellet weight, FPS, and even choking. All of these are the exact aspects which are being discussed here. And he also mentions the need for normalized test procedures, which wasn't done in the text which started all of the malicious palaver.

Lastly, Dr. Beeman mentioned that we're better equipped today technically, than even before. That is so very true! So the book might appear to be closed with respect to accuracy vs. speed, that is far from the case. Which means of course, we all need to keep an open mind to new developments. 

AZ, thank you for clarifying and filling in some details about your background, where you are coming from, what transpired here and in the past according to your point of view. You mentioned that you won't participate in this thread so some of my notes/questions below are rhetorical, and hope to be addressed by others, or in a new thread. For now, it seems like I am sitting in a classroom where all the professors left for good and I am stuck with some uncompleted homework/theories

A note on what you said: "People believe that shooting indoors involves no air turbulence and this is just not the case…A simple door opening to access the premises, the A/C turning or heaters inside barns generates enough turbulence to get you out of the 10 ring." I have the fortune to be able to drive about 45mins and shoot inside a 100 yard indoor air conditioned range. Assumed that the "wind" is not a variable, but always wondered if the air (conditioner) movement may be some factor because I always leave from the place feeling like a frozen meat. I still think it's negligible though.

You mentioned "laser and acoustic mics with equipment similar to what the ISSF currently uses at the Olympics and the very same equipment", so the place you work/hobby at, the Lab, seems like a place that some airgunner would love to get "lost" for days. Certainly great to have in place all the things that allow you to test out several theories which normally may take months of real-world testing to accomplish.

I think what piqued my curiosity most is this. "...how does anyone finds the velocity at which an airgun/pellet combo is the most accurate?” I added: “I am going to play it fair with you and everybody and I am letting you know that I already know the answer.…"
Is there a formula/equation? Or the "answer" can only be arrived with trial and testing (like most of us have to do)? Are the laboratory-conditions allow the elimination/minimizing of external variables to a level where it can be reliably measured by the equipment? Since the barrel/pellet combo is comprised of physical parts, each with its own physical characteristics, even with some external factors the combination of all those factors must be finite and they must fall within a measurable range. Probably better put: if a certain pellet in a certain barrel performs optimal at some single point within the 400fps to 1200fps range, that optimal velocity should be found (calculated?) in a sterile lab environment by analyzing millions of possible scenarios. Which otherwise for a shooter would be a trial and error of long days/weeks, or in best case a best guess that falls within a range. And all that work for only one particular barrel/combo which would have to be repeated for every other barrel/pellet by that airgunner. Would love to hear some details about this, albeit it makes me wonder how such potentially industry-revolutionizing information has never been made public. One of my previous threads asked that question: why don't the pellet and airgun manufacturers work together scientifically to match barrels with pellets (or vice versa) since obviously there is a correlation between these two that can lead to superb accuracy. Why leave such wide range of options open for the buyer having to have to experiment and trying to find the optimum pellet and the corresponding velocity?

And lastly, the idea of "Editorials or Tech Report" I believe would be of great use to this forum. I would also expand that to certain posts/threads which have arrived to a conclusion or some sort of lesson to be learned or an experience that merits preserving. Kind of a library of accepted and proven facts for reference purposes. Also, very accurate answers can be arrived to by "crowdsourcing" such as the stock evaluation website "Estimize" which constantly beats Wall Street's forecats by a large factor. The same could be done here and airgunners could vote on certain issues (ex. most accurate rifle you shot at 50 yards) which at the end establishes a consensus by the community. 

"Alan"I also asked if somebody knew why 570-585 was established as the velocity (ISSF) and why this velocity is very accurate?

I've never heard about this, and decided to do a bit of research. I find that Dr. Beeman has researched this as well, and covered the subject in several white papers. However, when I looked around the ISSF (International Shooting Sports Federation), I could find no mention of this specific range of velocity. But what I did find was references to spring-type airguns, in .177 caliber (the most popular caliber up to about circa 1985, and still the ISSF's official caliber), and their average velocity falls within this range. And no argument that these guns are very accurate out to about 15 yards. Past that, not so much.

In one of Dr. Beeman's white papers, he speaks of accuracy as a combination of factors—twist ratio, pellet BC, pellet weight, FPS, and even choking. All of these are the exact aspects which are being discussed here. And he also mentions the need for normalized test procedures, which wasn't done in the text which started all of the malicious palaver.

Lastly, Dr. Beeman mentioned that we're better equipped today technically, than even before. That is so very true! So the book might appear to be closed with respect to accuracy vs. speed, that is far from the case. Which means of course, we all need to keep an open mind to new developments.

Click to expand...

This is very interesting information Alan. And yes, the book is still open, even if some band of "accurate" velocities could be arrived to from the very thorough but time consuming testing data posted by Harry and Tom Gaylord and others. Short of knowing what formula or method AZ was alluding to which can be applied to any(?) barrel/pellet combo...and arrive to the optimum velocity for that particular setup..back to the long hours of trial and error for me. 

Agree, Fe. I'd say more and try to participate, but am worried that we are just throwing gasoline on a smoldering fire, the origins of which we know nothing about. I'll step back and lurk in the shadows, hoping my questions might someday get answered, whilst apologizing to any who felt I overstepped.

But, the slow rotation rate of ST-fired pellets, and the experiments to show it, are intriguing. I will have to do my own testing to verify, but they seem simple enough to reproduce.

"bent"Agree, Fe. I'd say more and try to participate, but am worried that we are just throwing gasoline on a smoldering fire, the origins of which we know nothing about. I'll step back and lurk in the shadows, hoping my questions might someday get answered, whilst apologizing to any who felt I overstepped.

But, the slow rotation rate of ST-fired pellets, and the experiments to show it, are intriguing. I will have to do my own testing to verify, but they seem simple enough to reproduce.

Click to expand...

Bent (and all other readers) the "smouldering fire" of which you write - and on which this fellow has constantly doused the gasoline of innuendo, libel, slander, spin, beat-up, and personal opinion presented as fact - that "fire" is AZ's own constructed straw man effigy of me which he himself then torches. It is an ancient strategy aimed at elevating one person's authority above that of another.
But it is to the great credit of all others here, that not one member here has chosen to burn me or even to toss a thimble full of gas on the effigy he constructed. I guess that even the newer members can recognize back alley behaviour towards a fellow member for what it is. Michael has had him remove most of the blight from this thread.
The last to go was AZ's big punch line in seemingly recruiting our forum founder, the wonderfully talented Holdover Ted, to prop him up with support for his anti Yrrah agenda. 
Viz., Quote Azuaro: "Ted Holdover agreed on what I said and he immediately responded to one of Yrrah’s claims: “BIG CLAIMS NEED BIG EXPLANATIONS AND MOST IMPORTANT…. BIG PROOF!!!”.

Well I contacted our founder, Holdover Ted, and this is what Ted has written.
"Hi Harry,
"I can assure you that I NEVER made any such "agreements" that your work is without merit. I have frequently said that exceptional and extraordinary results demand robust evidence. But, I usually point this quote at myself, or say it rhetorically (below is one such example from my facebook page).  
"I have seen no evidence that you are deliberately misleading the airgun community.  
"I have lost no sleep. I hope the same for you.  
ted"
Hopefully whoever AZ is, his vendetta is now at an end. 
Any research studies I may publish in this and other forums, will, as always, have the supporting data for all to assess on merit and to respond to constructively. That is my contract with your respected readership. 

Best regards, Harry G Fuller (member of the 2015 Australian World Championship Bench Rest Air rifle and Sporting Rimfire Team and I/C of rifle compliance).

Bent, check for new post regarding marking pellets for spin rate test.

Fair 'nuff, Harry. What dye did you use to mark the pellets in the ST barrel spin rate test? I might have some DyeChem machinist's blue around, but it's been awhile since I've seen it. Probably in the same place as my spare reading glasses...