Testing new discovery

[Insanity]

Taso maby ceramic beads like that used in internal tire balancing or steel shot.

[Nvreloader]

Taso

The mercury recoil reducers are going to be the heaviest weights, the C&H Research reducers is the one I am using,
they are still made today, per their site.

My lightest one is 5/8" diameter  x  4-1/2" long and weighs in at 2797.5 grs = 181.27 grams,
plus the tube clamp adds more weight etc.

The C&H reducers are made of steel rod, drilled to a certain depth,
and then Mercury etc is added and then sealed in a way that is leak proof.
They can also make any special size etc.

I hope that all the different modders list their weight/dimensions etc.

As soon as I finish testing the OEM style, I'll list the spec's etc.

Tia,
Don

[Mole2017]

I have to wonder if it is important that a dense material is used for the shot. That brings up a question: is it the movement of the shot in the oil or the movement of the oil in the shot that damps the motion?

If the shot is was does the moving, I would think something more closely matched to the oil (not necessarily the same density) would be better--it is less like to be "packed" or settled and thus more easily set in motion. I don't think anybody tried this with steel BBs, but I might have missed that in the discussion so far. BBs would be a step towards the less dense shot idea. If it works the same, worse, or better, we might or might not have something to pursue.

But if it is the oil, then an appropriately chosen porous media would be suitable instead of the lead.

Incidentally, mercury has a density 20 percent greater than lead, but its viscosity is closer to that of kerosene (about 50% greater than water). But ethylene glycol is nearly 20x more viscous than water (10x more than mercury) and of similar density as water.

Then you could go for glycerol/glycerine which has 1000x the viscosity of water and only slightly more dense than water.

[Hobbyman2007]

On my first series of tests , I had a hard time filling the cavity with steel shot and oil . The attachment did work but once I added an access hole to fill and got the shot / oil to fill the cavity it worked with some improvement.

[bear air]

Following, great job Knife.

[KnifeMaker]

Thanks for all the input Guy's. Hopefully I can re do some a a new post after appointments tomorrow. 


My dampener is 14.3 ox. with the included two scope o rings. Didn't weigh the picatinny rail attached to the LDC, which is an experimental Neil clague and very light. 


I would love for testers to give the particulars of their efforts and results.


Mike/Knife

[AlanMcD]

Wow, Mike - that is almost an added pound hanging out there on the end of your barrel.  I bet even if it were a solid mass, rather than the oil/shot dampener, that it could still have had a significant impact on the POI results.

I'm not sure I would want that much mass hanging out there on any rifle I would shoot offhand, but benchrest sure would be fine . . . .

[anti-squirrel]

Dampeners work excellent for high speed skiing, so this makes good sense.

So- since we now have it on good authority that these BAD devices work on PCPs, now one needs to be added to a springer- especially a lightweight twangy springer like my B-3.

Wow, Mike - that is almost an added pound hanging out there on the end of your barrel.  I bet even if it were a solid mass, rather than the oil/shot dampener, that it could still have had a significant impact on the POI results.

I'm not sure I would want that much mass hanging out there on any rifle I would shoot offhand, but benchrest sure would be fine . . . .

Actually a solid mass would not work anywhere near as well.  It would also vibrate at the same frequency, or could perhaps set up a harmonic.  The liquid-filled dampeners don't "move" as fast thus they break up the resonance.

[KnifeMaker]

Exactly, I did test a weight on the end of the barrel at almost exactly the same weight. It did not help groups at all.


If I make one for myself,  it will be lighter but same length more than likely, but only partially filled, with the rest blocked off.


I had long range accuracy in mind for this, so off hand shooting was not even considered. However, a shorter, lighter version would do well for hunting. A couple of testers tested exactly that, and why I didn't want to give detentions to Mr. R. Stern, or any other tester. I was looking for different takes on the theme being tested. 


Knife

[aceflier]

Im taking it this wont work on a shrouded barrel? Dont see how it could.

[Nvreloader]

Tim
I am running this type of device on 2 different shrouds, a QB-79 and Gauntlet, both 22 calibers,
seems to work very well, IMHO, still testing options/placements etc.

Tia,
Don

Im taking it this wont work on a shrouded barrel? Dont see how it could.

[Nvreloader]

Peter
I have a spare C&H Mercury recoil dampener, it is a 11 oz stock model, 7/8" x 4" long and a spare mount,
if you would like to try it, the only costs would be shipping to and from you/me.
Drop me a PM if you are interested etc.

http://www.mercuryrecoil.com/suppressors/index.htm#top

Tia,
Don

Dampeners work excellent for high speed skiing, so this makes good sense.
So- since we now have it on good authority that these BAD devices work on PCPs,
now one needs to be added to a springer- especially a lightweight twangy springer like my B-3.

[aceflier]

How about a hollow device like an LDC slipped over the shroud or barrel? Seems the best looking way to do it? Or would it not work properly?

[Nvreloader]

Tim

I don't know the answer, since we are all sailing in uncharted waters at this time, until more info is obtained/and tested. 

It might be the best you to test on your end, to see the results etc,
there has been a couple of posts as to the weight etc used by other testers etc.

I do know that I have both of these devices clamp right over the air stripper around the shroud,
and I can see the differences at 40 yds with 14.0 gr CMHP pellets, running right around 930 fps+.

HTH's,

Tia,
Don

[rsterne]

I have not made one yet, but I plan to start with the original design for a baseline.... I was thinking about a tubular one that would surround the barrel as well.... but to have enough room for the shot it needs to be either quite large in diameter or fairly long.... I am also somewhat concerned that there be enough annular gap between the inner and outer tube for the shot to move freely.... This issue would be even more pronounced with one made concentric with a shroud or LDC.... I would think you would want at least a 1/4" gap between the tubes.... Just a guess.... Sealing the end plugs to both an inner and outer tube is going to be a pain as well....

Bob

[Taso1000]

How about a bladder type enclosure like an inner tube or maybe a ziplock baggie that is wrapped around the barrel and in between the shroud?  I don't know how long a short but wide baggie would stay sealed though.

I'm in brainstorming mode here!  Lol

Thanks,

Taso

[darkcharisma]

I think the Annular type will be the best and easiest to make, using two different size tubes cut to length and cap with a machined 6061 t6 caps and JB weld. the smaller tube becomes the sleeve to the shroud and the bigger tube and caps will seal the materials in. can be mounted simply by sleeving on and secured by two clamps on both ends. this will be easier to move along the shroud to tune which position is best.

[anti-squirrel]

Peter
I have a spare C&H Mercury recoil dampener, it is a 11 oz stock model, 7/8" x 4" long and a spare mount,
if you would like to try it, the only costs would be shipping to and from you/me.
Drop me a PM if you are interested etc.

http://www.mercuryrecoil.com/suppressors/index.htm#top

Tia,
Don

Dampeners work excellent for high speed skiing, so this makes good sense.
So- since we now have it on good authority that these BAD devices work on PCPs,
now one needs to be added to aa springer- especially a lightweight twangy springer like my B-3.

I'm game, Don, but I'm gonna be back on the road shortly for a couple weeks, so I may not be the best choice unless folks are willing to wait for results.

For testing, I have a crunchy B-3 with worse handshock than a 78 # Bear Big-5 longbow, as well as my twangy CZ-634 and a Hatsan 95QE.  I can pull the shroud off the Hatsan- then all three barrels will be nekkid- and each gun is a different caliber. 

Any engineers that specialize in wave theory/propagation and harmonics?  Gut feeling tells me you'll want the center of the mass dampener at the 1/3 point of barrel length from the muzzle.  I'm an avid longbow shooter and dampeners work best on selfbows when added out-of-synch from each other and at non-harmonic points on the limbs.  Since this is a single "moving limb" (the barrel) it could be lots of fun to experiment with where the dampener actually resides.

[T3PRanch]

Suggestion:
Name your invention, and put it into a new thread. Give it a good start for the new comers of future years...

Mike's BAD device = Mike's Barrel Accurizer Dampener device


Matthias

Barrel Accurizer Damper Airgun Shot Stabilizer (I think you will get the acronym)


I built a coaxial version of this that threads to the muzzle but I simply don't have any bad shooting bullets to try!


I also discovered that the CF Tubing I used is not impervious to oil permeation (it leaks through the CF)

Thurmond,

What about silicone oil or possible thicker silicone grease?

I am also curious if there is enough movement and impacts of the lead shot to break up into small pieces?  I doubt it since lead is so malleable.  There's also Hevi-shot that's denser and non toxic.

Taso

I just need to use a better grade of CF Tube. The outer Resin covering was not done well and left tiny pinholes near one end. If I make another CF sleeve I will first put an extra gel coat over the exterior which should eliminate the issue. The lead shot is not going to impact anything sufficiently to break up because of the damping action of the oil on the movement of the shot. It is important that the shot can move so a thicker "grease" would effectively make the device a solid weight instead of a oil / shot filled damper!

[rsterne]

It is my understanding that the original had some air space inside.... I just weighed out 8 oz. of #7.5 lead shot, and it takes up about 3" of length inside a piece of 3/4" PVC "thinwall" pipe (1.05" OD)…. The tube is 0.92" ID, so a 3" length would be almost exactly 2 CI.... I looked up the density of lead shot, and it works out to 4 oz. per CI.... Therefore 8 oz. of shot should, indeed, take up 3" of length inside that thinwall PVC pipe.... The question is, should you FILL the rest of the volume with oil, if so, what oil.... or should you leave an air space, and if so, how big?.... If you are using Schedule 40 PVC pipe, it is only 0.82" ID, so 8 oz. of shot would occupy about 3.8" of length.... If you want 33% extra volume for the lead to move around in.... you need 5" of Schedule 40 PVC, but only 4" of thinwall PVC.... Both would be 3/4 full if you use 8 oz. of shot....

Incidently, if you have a shroud that is 1" OD, and slide a piece of aluminum tube over that, you will need the outer tube to be about 1.5" OD, depending on the wall thicknesses available.... Online metals sell 0.035" wall 6061-T6 in 1.50" OD (1.43" ID) and also 1.125" OD (1.055" ID)…. That has an annular volume just slightly less than the same length of 3/4" thinwall PVC, but more volume than the Schedule 40.... The problem I see is that the annular gap (0.153") is smaller than two diameters of #8 shot (0.09" diam), so the shot might jam when trying to move.... If that is indeed a concern, you need either a smaller inner tube, or a larger outer tube.... The next size up is 2.00" OD unless you go to a thicker wall.... The only reason I mention this, is that to fit one over an LDC it is going to become a pretty big OD....

Bob