Testing new discovery

[rsterne]

I made two dampers today, both from 3/4" thinwall PVC pipe (0.92" ID) with glued on caps.... One used a 4.0" long piece of pipe and 8.0 oz. of #7.5 shot and the other used a 2.0" long piece with 4.0 oz. of shot.... The long one was 4.5" LOA and weighed 10.5 oz. total and the short one was 2." LOA and weighed 6.0 oz. total.... The OD of the pipe is 1.05", and the caps are 1.30" OD....



I filed a notch halfway through the thickness of the side of the end caps to provide a groove to keep them parallel to the barrel.... I will use two cable ties on the long one and one on the short one.... The oil I used was Pennzoil Power Steering Fluid, which is basically a light hydraulic oil.... It has a viscosity of 37 at 40*C, which means it should be about 90 at room temp. or maybe a bit less....

The shot filled the cavity 3/4 full.... I added oil until no more air escaped, and then topped it up halfway between the top of the shot and the top of the tube.... ie the oil level was at the 7/8 full point.... In other words, the air space was 1/8 of the total volume.... When you glue on the top cap, you are compressing the air, to you have to hold the cap down for 30 seconds or so until the glue sets.... I then weighted the cap down for a few more minutes, just to make sure the cap didn't lift up from the air pressure inside....

I have not tested these dampers, and don't know when I will get the chance.... but they will fit any of the bottle guns I have.... I'm looking forward to a chance to try them out between Motel guests....

Bob

[Taso1000]

Just threw this snake oil contraption together. Going to zip tie it to the .25 mrod and shoot the 43gr bbt it absolutely hates. Licky if its 3” at 20yds.

4 2/34” shells of 8 shot with propylene glycol.

Now that would be cool to capture in slow motion!  We would be able to see what's going on with your clear container and liquid Tim!   

Taso

[aceflier]

Just threw this snake oil contraption together. Going to zip tie it to the .25 mrod and shoot the 43gr bbt it absolutely hates. Licky if its 3” at 20yds.

4 2/34” shells of 8 shot with propylene glycol.

Now that would be cool to capture in slow motion!  We would be able to see what's going on with your clear container and liquid Tim!   

Taso

My shooting table is full of grad party supplies. But after sunday I get it back. I’ll put the Iphone on it at 120fps slow mo and see what happens.

[BackStop]

Fascinating thread!  Whew, I am tired as I just now finished reading the entire thread... I am a very slow reader.  That is, if I want to comprehend what I am reading.
I don't know if this device would help my Nova Vista Freedom, but I can say that my DIY LDC did help.  It didn't help the Crosman Fire/F4 much on accuracy, but I do think it did help the Freedom somewhat.  I also don't get the harmonic "ping" from the hammer on the valve anymore after I put it on.


Sorry to digress. 


I will continue to watch this development.  It seems like there may be some useful applications for medium power AG's once you folks figure out the weights, placement and such.  Maybe even low powered AG's, again once weight and placement of the device has been fully tested.


Thanks for all of you who are testing and especially posting your results!

Oh, and thanks Knife for bringing this to everyone's attention!

Kerry

[KnifeMaker]

Thank You Sir!


I'm rather excited to see Robert using bb's, and it worked for him. I didn't think it would be enough weight. May very well be the ticket for low power/medium  pellet shooting!


Knife

[Nvreloader]

Guys,
With Knife's blessing, 

Here is some info that would be greatly appreciated and should be followed about your device you have built,
if there is anything info/spec's missing on the below form, just add a  line for it etc.

Design Form Spec Sheet of each build and the builder fills out,

Name:
Gun/caliber:
Pellet/slug/bullet weight/FPE/FPS range:
Total overall length and weight of device, including mounting system:
Attachment/clamp weight:
Tube diameter/material:
Amount of weight used/BB size/type/Lead/Steel:
Amount of Oil/Mercury used:
Photo's of device/targets etc:
Placement of device:
Comments on using:

Tia,
Don

[BackStop]

Thank You Sir!


I'm rather excited to see Robert suing bb's, and it worked for him. I didn't think it would be enough weight. May very well be the ticket for low power/medium  pellet shooting!


Knife

Dang Knife!  Watch the typos! (grin)
I was trying to figure out why Robert was "suing" bb's and who the heck IS "bb's" anyway... LOL!
Thanks again and keep up the good work!  Enjoy your posts and information!

[KnifeMaker]

Sorry, I was put on mussel relaxers after injury to back. (surgery two years ago). Was finally getting over and hurt it somehow. 


I don't do well on med's. Makes me loopy as a goose!


Corrected now. 

[BackStop]

Guys,
With Knife's blessing, 

Here is some info that would be greatly appreciated and should be followed about your device you have built,
if there is anything info/spec's missing on the below form, just add a  line for it etc.

Design Form Spec Sheet of each build and the builder fills out,
Name:
Gun/caliber:
Pellet/slug/bullet weight/FPE/FPS range:
Total overall length and weight of device, including mounting system:
Tube diameter/material:
Amount of weight used/BB size:
Amount of Oil/Mercury used:
Attachment clamp:
Photo's of device/targets etc:
Comments on using:

Tia,
Don

Add barrel placement to that list, although I am sure a pic would provide similar info, in these "testing" stages, measurements of barrel/shroud length and placement of the device *may* prove to be crucial.  Then again... maybe not.  But the testing has to be done first to determine that, one way or another.
Thanks again!

[BackStop]

Sorry, I was put on mussel relaxers after injury to back. (surgery two years ago). Was finally getting over and hurt it somehow. 


I don't do well on med's. Makes me loopy as a goose!

Yeah, now we know the REAL reason for the improvements in accuracy! LOL!
Thanks Knife, I hope you feel better without the medication soon!
Kerry

[KnifeMaker]

Way to go Don!


Yep, placement location, and whether lead shot or steel bb's. would be helpful as well.
Man, I had to correct the heck out of this short reply. GRRRR!!!


Thanks Kerry! Threw that Dayum medication away! I hat the feeling. 


Mike/Knife

[BackStop]

Way to go Don!


Yep, placement location, and whether lead shot or steel bb's. would be helpful as well.
Man, I had to correct the heck out of this short reply. GRRRR!!!


Thanks Kerry! 

I nearly always have to correct my posts... typos seem to be nearly like a religion with me.  I make them so often!
I wish the window for modifying posts was a LOT longer!  Sometimes I don't realize my mistakes until days later.
Anyway, thanks again and best wishes!

[Nvreloader]

Design Form Spec Sheet of each build and the builder fills out,

Name: Nvreloader
Gun/caliber: Gauntlet/22 caliber (OEM stock)
Pellet/slug/bullet weight/FPE/FPS range: 14.3 Crosman HP pellet/25 FPE - 900 FPS
Total overall length and weight of device, including mounting system:
4" long x .625" dia = 2797.5 grs = 181.27 grams= 6.40 oz
Attachment/clamp weight: Shotgun mag tube clamp = 464.9 grs = 30.12 grams = 1.06 oz
Tube diameter/material: Steel (OEM) C&H Recoil Suppressor
Amount of weight used/BB size: N/A
Amount of Oil/Mercury used: Mercury
Photo's of device/targets etc: Pending
Placement of device: Clamped under the shroud, Right under the air stripper that's inside the shroud,
22" from breach face, 4-1/2" from the muzzle
Comments on using: Tightens the group, less flyers, @ 40 yds, more testing ongoing

[BackStop]

Design Form Spec Sheet of each build and the builder fills out,

Name: Nvreloader
Gun/caliber: Gauntlet/22 caliber
Pellet/slug/bullet weight/FPE/FPS range: 14.3 Crosman HP pellet/25 FPE - 900 FPS
Total overall length and weight of device, including mounting system:
4" long x .625" dia = 2797.5 grs = 181.27 grams= 6.40 oz
Attachment/clamp weight: Shotgun mag tube clamp = 464.9 grs = 30.12 grams
Tube diameter/material: Steel (OEM) C&H Recoil Suppressor
Amount of weight used/BB size: N/A
Amount of Oil/Mercury used: Mercury
Photo's of device/targets etc: Pending
Placement of device: Clamped under the shroud, Right under the air stripper that's inside the shroud,
22" from breach face
Comments on using: Tightens the group, less flyers, @ 40 yds, more testing ongoing

Thanks Don!

[KnifeMaker]

Fine Job Mr. Don!

[K.O.]

This is my version of Knife's discovery. I am going outside to test, storm clouds rolling in.

what I like about it is it can even mount to the side like yours... have you played with positioning forwards/backwards..? wonder if a sweet spot shows itself and is different for say 32 fpe with BBT 30g and  28-30 fpe 14.3 CPHP/15.9 jsb/18g JSB...

I suspect some harmonics with my Bucc .22 and Urban with the BBT 30g at 620 and 671 fps... and near the same with both despite the shorter barrel of the Urby...

I have been blaming the fliers on maybe not a strict enough sort with the BBT but do feel that there is an element of harmonics with them also just because the groups were similar with both rifles 3 or 4 decently tight and them a flier...is also the case some what with  Eds Urban BBT 30g groups also... I tend to have fliers here and there with the 25.4g also... not so much with the 28g Eun Jin... and JSB 15g...

so maybe the fliers might not be the trigger jocks or imperfect casting alone....

might be a while before I make one for them but sure will be tuning in... I do think the dampening on top of being movable weight is definitely better than something like the Browning BOSS system...

have to admit I like the idea of clamping direct to the barrel or hanging it off the barell better than shroud mounting... think I like the idea of tuning the barrel bare using mounts something like these bar clamps with bolts that will go thru the shroud for mounting the damper...

https://www.crutchfield.com/S-vBdcSpGGbGQ/p_204FRC200/Bazooka-PR-FRC200.html

pretty sure part of the prob with mt AT 44 long .22 and 30g BBT is harmonics(.75 ish groups at 35 yards)...23" barrel one band and a rather stiff sudden L.W. size choke(down to .215")... so yep may be the first I try it on...

 but may be a while just bought materials for a back porch and then my youngest daughter decided she really  wanted a really low mileage 2013 Rio...my airguns/fun budget will be on temporary hold for a few months... tis worth it to help her have it 1/2 paid off with the down payment... but cash on hand is gone and the credit card... it will need a couple large payments in the next few months.. ...

So yep will be watching close this new application of   viscous fluid damping... shows a lot of promise...and not just for air rifles..! the .22lr bench and others  might want to pay some attention..

so yep will be watching and not joking about 4 giant(Texas size) rubber bands to suspend the muzzle..

looks to be a   "Heck" of a good move Mike..

[K.O.]

above was typed last night 18 post ago about Robert R's design forgot to hit post and fell to sleep...

Do wonder about tuning to best velocity pre damper vs post damper mounting..? with pellets well maybe pre and with cast rounds post..?

[K.O.]

Just threw this snake oil contraption together. Going to zip tie it to the .25 mrod and shoot the 43gr bbt it absolutely hates. Licky if its 3” at 20yds.

4  2 3/4” shells of 8 shot with propylene glycol.

are you talking about th 40g .25 BBT..? 

mine was about that at 40 yards... three things helped... they absolutely need a good leade... this is a very short round any rim left and not just  a smooth low angle into the rifling will tend to catch the rear drive band cocking the round in the barrel... #2... sizing mine only likes .2495-.250 ...#3... the shroud... the rear shroud mount has a o-ring on the breech side... loosen the grub screw... push it against the breech with some force while you re tighten the grub screw... this allows the o-ring to act as a damper... screw shroud back on just short of contact with breech... I am about .75" at 45 ish yards with limited testing with about 10 BHN rounds... I did get some fliers here and there out to 1.25" because of a very slight bit of rim left at the leade... catches once in a while (could feel it)...

oops forgot...#4, if you have a about .140 sprue hole it is to big... beg or buy a .22 caliber sprue plate... it is about .125 and will make it much easier to get clean sharp bases on the rebated tail/base...

[robertr]

 Kirby I was testing some more yesterday , it was a little breezy but found it works best by the muzzle as in the pic. I am also going to adjust internals to see if there is a difference.

 Toughest thing is to find conditions the same so the test will be more accurate.

[K.O.]

Kirby I was testing some more yesterday , it was a little breezy but found it works best by the muzzle as in the pic. I am also going to adjust internals to see if there is a difference.

 Toughest thing is to find conditions the same so the test will be more accurate.

yep indoor ranges do have their uses...