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Author Topic: Crude Harmonic Dampener  (Read 729 times))

Offline SpiralGroove

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Crude Harmonic Dampener
« on: October 02, 2021, 08:33:45 PM »
Hey Bob,
Do you believe this steel collar has much chance of reducing the harmonics of my RAW barrell?

The split collar weighs 6.3 oz and can be clamped on pretty tight - it's not gonna move.  Adjusting is very Crude - loosening 5 mm cap screw and sliding to different locations.
  • Bothell, WA
PCP's:
AR2079A-HPA (.177)
AR2079A-HPA (.22)
BSA R10 (.177) Huma Regulated
RAW HM1000x LRT Camo - (.22)
RAW HM1000x LRT RED - (.25)
QB78 (.177) OEM

Pumper's:
1973 Benjamin Franklin 342
1984 Benjamin Franklin 347

Springer's:
Beeman R9   (.20) - Circa 2019
Beeman R10 (.20) - Circa 1988
HW30S (.177)
HW35E (2) (.177)
HW35E - Silver (.177)
HW50S (.177)
HW50S - Silver (.177)
HW80 (.20)
HW95 Hybrid (HW98 stock) (.177)

Offline rsterne

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Re: Crude Harmonic Dampener
« Reply #1 on: October 02, 2021, 10:34:01 PM »
Yep, I think that will work.... You may find that finding the correct position may be easy.... or you may find that adjustment is critical and a matter of a few thou may make a difference.... I have heard of both situations....

Bob
  • Coalmont, BC, Canada
Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsenal:
1750 CO2 Carbine, .177 Uber-Pumper, .22 Uber-Carbine, .25 Discovery, 2260 PCP 8-shot Carbine, 2260 HPA (37 FPE), 2560 HPA (52 FPE), XS-60c HPA in .30 cal (90 FPE), .22 cal QB79 HPA, Disco Doubles in .22, .25 & .30 cal, "Hayabusa" Custom PCP Project (Mk.I is .22 & .25 cal regulated; Mk.II is .224, .257, 7mm, .308 & .357; Mk.III is .410 shotgun and .458 cal), .257 "Monocoque" Benchrest PCP, .172/6mm Regulated PCP and .224/.257 Unregulated, Three regulated BRods in .25 cal (70 FPE), .30 cal (100 FPE) & .35 cal (145 FPE), .257 Condor (180 FPE).

Offline SpiralGroove

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Re: Crude Harmonic Dampener
« Reply #2 on: October 02, 2021, 11:29:24 PM »
Yep, I think that will work.... You may find that finding the correct position may be easy.... or you may find that adjustment is critical and a matter of a few thou may make a difference.... I have heard of both situations....

Bob
Thanks for replying🙂.
Roughly, how much weight becomes too much?
Kirk
  • Bothell, WA
PCP's:
AR2079A-HPA (.177)
AR2079A-HPA (.22)
BSA R10 (.177) Huma Regulated
RAW HM1000x LRT Camo - (.22)
RAW HM1000x LRT RED - (.25)
QB78 (.177) OEM

Pumper's:
1973 Benjamin Franklin 342
1984 Benjamin Franklin 347

Springer's:
Beeman R9   (.20) - Circa 2019
Beeman R10 (.20) - Circa 1988
HW30S (.177)
HW35E (2) (.177)
HW35E - Silver (.177)
HW50S (.177)
HW50S - Silver (.177)
HW80 (.20)
HW95 Hybrid (HW98 stock) (.177)

Offline rsterne

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Re: Crude Harmonic Dampener
« Reply #3 on: October 03, 2021, 01:20:59 AM »
No idea.... However a quick check of .22LR tuners shows 4.75 to 8 oz.... Knifemakers shot filled tuners ran 4-8 oz. of shot.... and up to 14+ oz. total weight....

https://www.gatewaytoairguns.org/GTA/index.php?topic=157680.0

My tuners had 5 oz. movable with a total of 7 oz....

Bob
« Last Edit: October 03, 2021, 01:31:31 AM by rsterne »
  • Coalmont, BC, Canada
Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsenal:
1750 CO2 Carbine, .177 Uber-Pumper, .22 Uber-Carbine, .25 Discovery, 2260 PCP 8-shot Carbine, 2260 HPA (37 FPE), 2560 HPA (52 FPE), XS-60c HPA in .30 cal (90 FPE), .22 cal QB79 HPA, Disco Doubles in .22, .25 & .30 cal, "Hayabusa" Custom PCP Project (Mk.I is .22 & .25 cal regulated; Mk.II is .224, .257, 7mm, .308 & .357; Mk.III is .410 shotgun and .458 cal), .257 "Monocoque" Benchrest PCP, .172/6mm Regulated PCP and .224/.257 Unregulated, Three regulated BRods in .25 cal (70 FPE), .30 cal (100 FPE) & .35 cal (145 FPE), .257 Condor (180 FPE).

Offline Greg_E

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Re: Crude Harmonic Dampener
« Reply #4 on: October 22, 2021, 04:49:21 PM »
What is the theory on tuners? Middle of barrel, out on the end, etc.?

I can see where out on the end will change the inertia of the end of the barrel and hopefully let the projectile pass before moving. But not sure if this is the theory behind how they work.
  • USA, NY, Syracuse

Offline rsterne

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Re: Crude Harmonic Dampener
« Reply #5 on: October 22, 2021, 05:20:00 PM »
Most adjustable (threaded) tuners are mounted at, or beyond, the muzzle.... By fine adjustments you can vary the position of the muzzle when the projectile exits from it.... This can provide a dramatic reduction in vertical stringing at one range, which is why it is used by benchrest rimfire competitors.... It can also be used to get a "node" at the muzzle, where barrel movement is at a minimum.... Having the weight at the muzzle also reduces the frequency and amplitude of the vibration there....

The other alternative is a sliding weight that you move along the barrel to adjust the harmonics.... I think they are mainly used to get a "node" (where the movement is minimal) to occur at the muzzle....

Bob
« Last Edit: October 22, 2021, 05:22:38 PM by rsterne »
  • Coalmont, BC, Canada
Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsenal:
1750 CO2 Carbine, .177 Uber-Pumper, .22 Uber-Carbine, .25 Discovery, 2260 PCP 8-shot Carbine, 2260 HPA (37 FPE), 2560 HPA (52 FPE), XS-60c HPA in .30 cal (90 FPE), .22 cal QB79 HPA, Disco Doubles in .22, .25 & .30 cal, "Hayabusa" Custom PCP Project (Mk.I is .22 & .25 cal regulated; Mk.II is .224, .257, 7mm, .308 & .357; Mk.III is .410 shotgun and .458 cal), .257 "Monocoque" Benchrest PCP, .172/6mm Regulated PCP and .224/.257 Unregulated, Three regulated BRods in .25 cal (70 FPE), .30 cal (100 FPE) & .35 cal (145 FPE), .257 Condor (180 FPE).

Offline lefteyeshot

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Re: Crude Harmonic Dampener
« Reply #6 on: October 22, 2021, 08:54:42 PM »
FYI: I bought some rubber Limbsaver barrel vibration dampeners. They call them 'Sharpshooter X-Ring Barrel Deresonator'. I haven't experimented with them much yet. The directions say slide them on supported barrels 3/4" from the stock and on floating barrels 3/4" from the muzzle.
  • Savannah, Ga.
Diana 470th, 56th, 350 PC
BSF c60
Parrus wood
Dominator 200 carbine
Proxima
Synergis
Win. 1000w, 800w, 1100w, 1100s
Webley .22 Jaguar
Mendoza RM2800 repeater
Norica Massimo .22, Black Eagle
CZ631, 2 CZ634
Hammerli X2 dual cal.(Mendoza)
Beeman RS2.177/.22
Air Hawk Elite wood T.H.
Storm in Benj. T.H. stock, GRT
3 Crosman 3100(Spain)
Steoger Ducks Unlimited X3
RWS93 (Spain)
RWS320 (China)
2 TF99, TF59 GRT
TF89 (chopped, shrouded Beeman .22 Brl.)
B40, B26-2, B21, B20
2 B3-1
4 Peak B4-2
Model 62
2 QB6,
2 QB57
2 Fast Deer
2 B3-1AK
AR2078B, AR2078TH
Zogunz Hawk 010 .22 (Phil.)
XSP 120D single stroke dual cal. pistol
P17, Steoger XP4 single stroke pistol

Offline Nvreloader

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Re: Crude Harmonic Dampener
« Reply #7 on: October 23, 2021, 06:45:31 PM »
Guys,
FWIW

I just installed another MAD device on my Varmint 22 cal, that I have been testing with resized pellets etc.

The before group straight out of the can shot into a shotgun group of 3-1/2" x 1-1/2",
@ 50yds = 900+ fps, using stock Crosman OEM pellets 14.3grs

The best group for .2170" head sized OEM Crosman pellets = 5.300" x 2.25", same 50 yds,
nothing changed from the above rifle settings.

Installed a Mercury fill shotgun chamber MAD devise,
and reshot from the same OEM Crosman tin, and recorded a 2.030" x .500" at the above yardage.

Resized .2170" head pellets from the same can, landed in a group that was .930" x .600",
all groups were measured outside edge to outside edge.

This Mercury filled MAD devise is pictured here on pg#19 and post #372,
https://www.gatewaytoairguns.org/GTA/index.php?topic=157680.360
I installed it right behind the LCD on the barrel.

This is the third time, I have tried and install this device, on 3 different type of 22 cal PcP rifles,
and I have seen great improvements in the total overall group size,
with reduced scattered pellets, and cleaner rounder group sizes,
I'll be testing further all head resized pellets to compare against the first series shot,
to see the final results.

Tia,
Don
  • Western  NV
Sheridan 64/67 yr models, 20 cal/Hammerli 850 Air Mag -17 cal x 2, + 22 cal /QB-79 - 22 cal /Guantlet - 22 cal / Crosman 150 - 22 cal, Second Variant Model /Crosman 160 - 1st Variant Model - 22 cal /MRod Varmint 22 cal /Sentry 705-2 - 22 cal /Sentry 705 - 9T - 25 cal / Dar 17 cal /22 cal Discovery
CF 4500 45 min SCBA tanks x 3, w/SB F-10 compressor

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