Barrel Harmonic Wave DeResonator Trial With Shaft Collar
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- Опубликовано: 8 фев 2025
- Equipment: RimX .22LR, WOOX Exactus Stock/chassis, Mueller Works 24" bull barrel, Trigger Tech Diamond, Eley Tenex, Randolph Machine Front Rest, Protektor Rear Rest. I've been reading a little on barrel harmonics, specifically looking for understanding of the sinusoidal wave and its characteristics in regard to projectile behavior on muzzle exit and ways of influencing.
There are a few reports and articles, some written with a decidedly technical engineering style, some with readily understandable basic fundamentals. Then there are available products offering a means to manipulate the harmonics for a beneficial response.
One person posted a video on the $2.00 solution. He was using a shaft collar. I viewed it. It had inherent logic, and his methods were reasonable.
I measured my barrel diameter (1.21") and the nearest size shaft collar (1.25"), and decided to give it a try. It is a 2 part unit (no harm to the barrel), quality stainless, appears semi-polished. A little gun oil on the inner wall and off to the range.
(I noticed my Anschutz target rifle has the muzzle end of the barrel diameter at 1.00" for 2+ inches from the end, tapered to a 0.92" remainder barrel length. With slots machined in, the end is apparent design for front site placement. However, (I'm thinking) the wider 2+ inch length of muzzle end might just affect barrel harmonics in a positive accuracy way. (?).
More encouragement to try the shaft collar idea on the RimX.)
So, back to the shaft collar. With zero engineering or mathematical rational I decided to place the collars at 1/2" from muzzle end to start, with the rear collar 1/2" from the front collar. Again, no scientific justification. I thought if a touch of a stock can upset a free floating barrels accuracy (most agree on this point) by disturbing harmonic resonance (?), then collar on the barrel can affect the frequency characteristics (?). (My apologies to engineers, gunsmiths and mathematician's sensibilities who continue to read this after the first sentence). Again, with no particular mathematical model in mind, I decided on 1/2" increments of movement for the test. I had just over 8" of distal barrel length to work with up to the stock forend.
Group patterns initially showed no obvious pattern to my untrained eye, but it looked like target 3 and 6 ( 1.5" and 2" from muzzle) almost wanted to form, then began to spread. Likewise target 13 (5.5" from muzzle) looked good, excluding the flyer, and my attention was starting to wander, so almost stopped there, but was close to the end of the length so kept shooting.
That led to target 16 (7" from muzzle) and 17 (7.5" from muzzle). In retrospect I'm pretty sure I can see slowly forming circles in groups 13-14-15, culminating in 16 and especially target 17! Continuing to target 18, which is at 8" from muzzle end, it appeared to me the wave was oscillating out of its maximum 'best'.
Settling (a surprise indeed!) on target 17, (which was 7.5" from muzzle end with the front collar at the 7.5" mark), the group measured 0.19" CTC.
Not wanting to let this go, with temperature 34*F, and ammunition out in the cold for 1-2 hours at this point, I shot two additional 'collared' groups on target 22 and 23. These two groups of 5 rounds measured 0.25" and 0.24" respectively. This definitely had my attention. So, I needed a control group(s). I removed the collar. All other variables were unchanged. Same weather, Eley Tenex, rifle, time of day, cold hands, shooter, etc.
The two 'non-collared' control groups at target 24 and target 25 differed markedly from the two 'collared' groups immediately prior.
At this point I did shoot some points on the sight-in target which showed well but decided to save an accuracy trial with the shaft collars at 7.5" for another day as I was a bit tired from a long shoot.
One final note: This build has already shown itself to shoot groups with this precision.
This without the collar, using Lapua ammunition which this build was
chambered for.
Desert Precision Gunworks model of excellence!
Just seeing if I could 'Gild the Lily' ; ).
Every brand of what we call a barrel tuner today watching this is screaming STOP! at the screen lol. Every gunsmith thinking of how many potential lost customers for barrel threading he'll lose is making him pull his hair out lol. It's a good test now to see if it translates to the next lot number of ammo and how well it repeats over time. Looking forward to more videos in 2024. Merry Christmas!
I have a barrel tuner that fits one of my barrels. Now I have two shaft collars that fit another barrel. When this interest wanes, they will find their place on the shelf. In the end its the original rifle and time on the range 😆.
Wow, glad to see my article was useful to someone. Nice work, I will try the collar when I get my new barrel... Charlie
See what you started Charlie! 😉. Nice video on your part!
I watched a video in which a guy used some kind of a plumbing compression fitting to similar results. $2.00 part! I have yet to experiment with it but it looked promising!😅❤❤❤
I have 3 home made tuners made from brass. So far only one works as intended but I never tried them behind the muzzle as you did in this video. 2 thumbs up!
Self-determined innovation! Even getting to the moon has its roots in Orville and Wilbur looking at and using bicycle parts in a different way. 🧐
I wish I had a nickle for everytime someone asked what is that thing? They would have paid for themselves,@@22rimfireultra67
Great info. Thanks 👍. Merry Christmas to you and yours
Interesting results to be sure. Merry Christmas to you as well!
Great video, subbed and liked. Going to try it on my bergara bmr.
Very Interesting. Thanks
Interesting, love that you did some repeatability testing followed by removing them. Curious if there was any cleaning of the barrel during the testing, great video!
Cleaned the barrel when new, before any range time. Prior to this day the barrel had 200 rounds of ammunition through it from new.
I fired 20 rounds for fouling before aim at the One Inch Targets trial in this video.
No cleaning during testing.
I put a dry 1" round on a 'PatchWorm' for one pull through to pick up residue after each outing.
After the next outing (approximately 400 rounds total since new), I'll saturated a 'mop' with Bore Tech C4 using a pistol rod from the breech end and let it soak for 10 minutes. After withdrawing the mop from the breech end, I'll saturate a 1" cotton patch with C4 and pull it through (breech to muzzle) with the 'PatchWorm'.
Then with the 'PatchWorm', 3,4, 5 ot 6 more round patches until dry and clean.🧐
Seen another YT vid called "$2 barrel tuner" where guy used a single shaft collar (non split). Got good results also but once he found a node he started moving in .001" increments. He ended up about 1.5" from muzzle.
Yes I know that video. It was one of the 'motivators' for my trial.
One day I will spend some time for refinement of placement. When the season warms up in a few months.
Why two and not just one? I use one on mine and works great.
Hello, where did you purchase the barrel clamps? thanks
Shaft collars (several different diameter sizes) , on Amazon: 1.00" Bore Diameter - Clamping Two Piece Shaft Collar - 303 Stainless Steel
Is it more difficult to tune a thick barrel vs a thin barrel?
I'm not the one to answer that, being I have only poorly tested tuners and never really used them. But there are rational answers to your question on various web sites and youtube channels.
Hey, try weighting the ammo first it helps with fliers.
Interesting results. I'd also try repeatability at 7". That group looked to be almost the same as 7.5".
That seems to be the place that makes the barrel 'purr' 😻!
At least for that day!
My CZ 457 MTR 20" shoots a .3o inch group at 50 meters using SK Rifle Match, if there is more than one hole it's more often than not my fault. I get the impression that your rifle doesn't like the ammo.
Eley ( approx. 0.038" rim thickness) is not its ammunition of choice. The rifle was chambered for Lapua ( approx. 0.043" rim thickness). I knew this when I did this video. Having more Tenex on hand than Center-X, I chose Tenex to use. I had some decent groups with Ctr-X a couple of weeks ago. Will get back to it soon hopefully! 😉
👏👏👏👏👏
You are on to something. Glad to see you repeated the groups.
The control groups offer a little validity 🤓. I hope to extend this a bit in the not to distant future (winter time and all)🥶.
Why are you using two, when it should be one weight moving? And why are you fairly randomly moving half-inch increments, when the frequency of the vibration can be thousandths of an inch, in wavelength? If you want to adjust the length of a full sine wave length, then your adjustments have to be in factions smaller than the wavelength! In other words, your testing was immediately invalid, non-systematic, imprecise, and orders of magnitude too coarse to detect anything. It seems you either don't understand the principles of such tuning, or you were just making a prank video?
Thanks for your observational analysis. I somewhat agree with your academic critique.....for the most part. 🤔