Testing new discovery

[Hobbyman2007]

Right now I’m not sold on the whole bigger is better . Without having my device in my hands right now and going from memory I think my total weight was 171 grams and it did make enough of a difference that was don’t want to modify it . I may make a bigger one for testing and if it proves to be better performing great , if not even better.

[Nomadic Pirate]

OK, it seems that this works and it sure makes sense,

I see this being a great ad on for those that chase extreme precision for long range shooting,...I was interested, but for my airguns application I rather not ad on more stuff on the gun

[darkcharisma]

I wonder if only using 8 oz worth of overall weight can make a difference?

[rsterne]

Knife said the original used the shot from 4 or 5, 12 ga. shells.... That would likely be 5 to 6-1/4 oz.... His 14.3 oz. total weight was including the plastic housing, the mounting bolt, 2 scope rings, and the oil.... I think if you take away all those things, that would leave about 8 oz. for the shot....

Bob

[Nvreloader]

The average 12 ga shot shell loads run from 7/8 oz to 1-1/2oz, depending on shot size, in the OEM loadings.
 
What the unknown is, is the shot size/amount of shot plus the amount of oil used etc.

One of the OEM names for this device is called = Okie Shootin-Cushion, here is what the device looks like,
it comes in 2 different sizes, with what I have been able to find out so far, still researching etc,
my Google fu is not strong. 

https://www.ebay.com/itm/Okie-Shootin-Cushion/183805427323

As soon as I get time, I'll see if I dismantle both, (without destroying them), I have one of each size,
and post the info I find etc.  That should provide more info needed.

HTH's
Don

[rsterne]

I have been looking at the viscosity of various fluids and came up with the following approximate values at room temp....

Water.... 1
Mercury.... 1.5
Ethylene Glycol.... 18 (anti-freeze)
Hydraulic Oil ISO 15.... 35 (many ISO Grades are available)
Automatic Transmission Fluid.... 70 …. 10 wt. Shock Oil, Power Steering Fluid, and ISO 32 Hydraulic Oil are all about the same viscosity....
SAE 10 Motor Oil.... 140
SAE 30 Motor Oil.... ~350 (correction)
Glycerine…. 950

I doubt you would want anything thicker than that.... JMO....

Bob

[rsterne]

The shot size won't have much effect on the density (the volume occupied by a given weight).... but it would affect how the shot moves in the oil.... or through a gap between two tubes....

Bob

[Mole2017]

I have been looking at the viscosity of various fluids and came up with the following approximate values at room temp....

Water.... 1
Mercury.... 1.5
Ethylene Glycol.... 18 (anti-freeze)
Hydraulic Oil ISO 15.... 35 (many ISO Grades are available)
Automatic Transmission Fluid.... 70
10W Motor Oil.... 140
30W Motor Oil.... 280

I doubt you would want anything thicker than that.... JMO....

Bob

But if you did...how about glycerine? Your scale is a little different than the data I've seen, but close enough that glycerine would come in at about 950 or 1000. That's pretty stout, but still liquid.

Seems like there might be an optimal configuration for any liquid/pellet shape/size/material configuration you might choose. If I follow correctly, the object is a mixture that simply dissipates energy. Tuned dampers are one thing, deadening slushes are another**, but there are also other tricks. For vibration control of panels on things from cars to hard drive covers, one technique is to simply make a laminate of several sheets of metal. The key is to use a "thick" adhesive layer between them, which accomplishes the damping action. Would one or more loosely nesting tubes or sleeves "glued" over the barrel, shroud, or LDC and each other accomplish the job? Hmm...

**Don't use waterless hand cleaner. Have you ever held a jar of that in your hand and tapped the side of it? Just about zero damping ability--you can almost hear the "bonk" from your tapping it, but you can certainly feel it.

[rsterne]

I had the wrong value for SAE 30 Motor Oil, it is about 350, not 280.... Yes, Glycerine is 950, I added that and corrected the 30W above....

Bob

[darkcharisma]

Well now. The dead blow hammer now has no oil compared to the original dead blow hammer. And it works as it should. knife said this device spring off of that of a dead blow hammer.

I think oil needs to be thin in viscosity for the shots to move freely just as fast as the force it opposes to make it effective in dampening/canceling out the negative hamornic vibration or jump. The deadblow hammers now doesn't have fluilds and works with only half of cavity filled. Same concept could be applied here Right???

[superchikn]

I have a Bayer aspirin bottle full of Mercury sitting on the shelf.  It was my grandfathers.  It must weigh 3 pounds.  If I duct tape it to the muzzle...
Anyway, since HG is fluid and denser than lead it is much more versatile than lead shot and could offer some great solutions for many situations. 

For example My Liberty or Freedom are shrouded.  The shroud is only about 2 1/2" longer than the air tube on my liberty so there would not be much room for a hanging piece, and it would obscure the air gauge.
The barrel is roughly 4 inches shorter than the shroud and the barrel block is about 5 inches back from the end of the barrel. 

I'm thinking mercury in something like a straw although much more durable and secure, if perhaps a bit malleable could be slit in between the barrel and shroud behind baffles and in front of barrel block.  made to appropriate length multiples could be used as required.
These could also be integrated into LDCs or adapted to mount externally on a barrel or shroud with a much lower profile than other configurations. 

Obviously there is more to it than hot glueing some Mercury into a few 5" straws and dropping them into my shroud between monocore baffle and barrel block but perhaps food for though.

[superchikn]

Well now. The dead blow hammer now has no oil compared to the original dead blow hammer. And it works as it should. knife said this device spring off of that of a dead blow hammer.

I think oil needs to be thin in viscosity for the shots to move freely just as fast as the force it opposes to make it effective in dampening/canceling out the negative hamornic vibration or jump. The deadblow hammers now doesn't have fluilds and works with only half of cavity filled. Same concept could be applied here Right???

I think we need some assemblies made in clear tubing and recorded with a high speed camera.  I'll bet the fluids, especially the Mercury do some neat things!!!

[Nvreloader]

Ray

I don't think you would need to tape that whole bottle to the bbl,
find a smaller container (unbreakable) that will hold 6-8 oz and can be sealed securely,
just use some thin wire and make a loop to fit around the bbl/shroud,
then slide the container back and forth to see the results, while shooting etc.

I also have a 2" dia bottle of mercury, recovered from Gold dredging in the Yuba River/Ca, early 60's,
used a potato to recover it from the Gold........... 

Tia,
Don

[superchikn]

Don I was kidding about taping the bottle on.  It is way too much and the bottle is glass with a screw on lid.  That's how old it is.
For the most part my grandfather who was a welder at the shipyards and for Budd co. recovered the HG from switches.  Cool stuff.  When  I was a kid once in a while he would give some of us a little bit to roll around in the palm of our hand.  That and melted Woods metal.

[rsterne]

I particularly like the idea of hiding vials of Mercury inside an LDC.... They would have to be strong enough to never leak, and mounted securely enough to do the job.... but it should work.... It is almost twice as dense as lead shot, so 1 CI would weigh nearly 8 oz.... Since it is a liquid, you would not need as big a gap between the walls of concentric cylinders, which would make such an arrangement slimmer than with lead shot....

Bob

[Nvreloader]

Guys
Food for thought and questions?

Since this harmonic dampener was originally designed for a bow, and as anyone who has shot a bow,
either recurve or compound type knows, when the arrow is released, the bow WILL jump forward a lot,
and out of your hand/grip, due to the normal reaction of the mechanics of the bow.

On my Jenning's Arrowstar/Shooting star bows, I made/had a dampener on each,
a hunk of lead/spring on a steel bolt, I was shooting @ 80#'s/overdraw, 24" arrow length,
I learned that, I could decrease the lead weight a little at a time, until the bow would set perfectly still,
and straight up/down after the release and still maintain accuracy etc.
I would believe that NONE of our air rifle are that violent in reaction?

Question:
It has to be the combination of weight and the possible movement of the shot,
that changes/assists in the accuracy of the shooting?

As we have all ready know, plain weight doesn't work

Just how much weight/oil combo is really needed, to be effective,
as each shooting application is different, right?

Tia,
Don

[superchikn]

I particularly like the idea of hiding vials of Mercury inside an LDC.... They would have to be strong enough to never leak, and mounted securely enough to do the job.... but it should work.... It is almost twice as dense as lead shot, so 1 CI would weigh nearly 8 oz.... Since it is a liquid, you would not need as big a gap between the walls of concentric cylinders, which would make such an arrangement slimmer than with lead shot....

Bob

Thank you for spelling that out.  That is exactly what my though process was. 

Thin wall brass tube would be an option, strong, easily sealed, malleable, lightweight. 

Any interaction problems with brass mercury steel and aluminum?

[shorty]

Knife,
Cool idea, I like it and can see why you would want to incorporate it into an LDC.

While waiting for the release, I guessed so many times with myself and could only think of this for mini14's.
https://www.accu-strut.com/

From reading your post and others,
I can't tell if a viscous solution is really needed and that's what has my curiosity. Would you think that a (adjustable spring loaded plunger) on the shot would act similar to a viscous material ?

[rsterne]

Mercury can form an amalgam with aluminum, lead or gold, and can combine with copper (the main component of brass).... Generally the oxide coating on any metal will prevent a reaction, but if the metal is scratched through the oxide layer, then the mercury will combine with it in some way.... As kids, we used to coat copper pennies with Mercury, and they looked like a shiny dime (hey, I'm still alive)....  ….  However, it is relatively unreactive with steel.... I don't know about brass, it may well depend on the alloy....

Tim, I think the shot has to be able to move relative to itself, in reaction to barrel vibrations.... What you are suggesting might work better to reduce recoil, IMO.... I think the fluid is mostly to prevent the shot from rattling and to protect it from beating itself to dust.... I plan to try a 10 weight oil, at least in the first one.... I want to get some synthetic 10W shock oil to try Knife's bullet lubing, so I may just use that....

Bob

[superchikn]

Mercury can form an amalgam with aluminum, lead or gold, and can combine with copper (the main component of brass).... Generally the oxide coating on any metal will prevent a reaction, but if the metal is scratched through the oxide layer, then the mercury will combine with it in some way.... As kids, we used to coat copper pennies with Mercury, and they looked like a shiny dime (hey, I'm still alive)....  ….  However, it is relatively unreactive with steel.... I don't know about brass, it may well depend on the alloy....

Bob

I guess more specifically, if a thinwall brass "vial" containing mercury is between an aluminum shroud and a steel barrel might there be any issues?!