Author Topic: Internal Air Stripper Prototype  (Read 2459 times)

lee545

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Internal Air Stripper Prototype
« on: March 02, 2017, 01:37:30 AM »




I have had this idea floating around in my mind for a few days and finally had the time to build the first concept in CAD. The goal is to improve efficiency in redirecting more air in the opposite direction of the pellet with the brass colored insert positioned about an inch from the muzzle. The bore has a tighter diameter, .05 larger than the nominal size of the pellet. Without the insert, I have been successful so far in reducing the pulse and the fallowing bark by having just a tight bore without the insert. As much as 10 dbs by just swapping out strippers.   



Motorhead

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Re: Internal Air Stripper Prototype
« Reply #1 on: March 02, 2017, 08:28:17 AM »
Yup ... good idea, tho not a new idea having among many already done it  :o

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lee545

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Re: Internal Air Stripper Prototype
« Reply #2 on: March 02, 2017, 10:20:12 AM »
Nothin is new under the sun....I haven't seen that design before but I like the 2 chamber design. Thanks for sharing. I was looking at a Hatsan air stripper what lead me to ask the question of what if I combine it with the current one I use? Glad it's been done before because then I having a base line to measure against.

Motorhead

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Re: Internal Air Stripper Prototype
« Reply #3 on: March 02, 2017, 11:15:16 AM »
It is common among most ... that at AIR GUN pressures the use of a STRIPPER is more bling than function simply because the air accelerating around an air gun pellet is so substantially less than a powder burner.

For most who find gains in a stripper fitted rifle it is one of harmonics or barrel whip over that of air disturbance causing inaccuracies.   

Where one will / can find help from a stripper as shown above is that of AIR DIVERSION into the overlaid shroud tube to help in quashing air impulse energy.  While air pressure above ambient will always seek the path of least resistance, The sound waves being somewhat diverted by the stripper generally can help quiet down the report.
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lee545

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Re: Internal Air Stripper Prototype
« Reply #4 on: March 02, 2017, 12:53:19 PM »
It is common among most ... that at AIR GUN pressures the use of a STRIPPER is more bling than function simply because the air accelerating around an air gun pellet is so substantially less than a powder burner.

For most who find gains in a stripper fitted rifle it is one of harmonics or barrel whip over that of air disturbance causing inaccuracies.   

Where one will / can find help from a stripper as shown above is that of AIR DIVERSION into the overlaid shroud tube to help in quashing air impulse energy.  While air pressure above ambient will always seek the path of least resistance, The sound waves being somewhat diverted by the stripper generally can help quiet down the report.

Thank you for the explanation. I will carry that with me as I test my 3d model. If it can help dull the report without having to lengthen my full length shroud, that is what I am after. 

Christopher

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Re: Internal Air Stripper Prototype
« Reply #5 on: March 03, 2017, 02:14:23 AM »
Nice work on the air stripper lee545. Looking forward to more test results.


Chris
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Christopher

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Re: Internal Air Stripper Prototype
« Reply #6 on: March 03, 2017, 02:22:55 AM »
rsterne incorporated a similar concept, just a little different execution and being dual purpose as well. He has named his arrangement the VBT.

Here's the read as you can probably see for yourself better than I could explain it, refer to post #29: http://airgunguild.com/pcp-c02-and-helium-powered-airguns/regulated-disco-double/15/

Chris
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Windmeister

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Re: Internal Air Stripper Prototype
« Reply #7 on: March 07, 2017, 11:16:58 AM »
The one "challenge" all these design have is that it relies heavily upon the concentricity of thread on the outside of the barrel to the bore centerline.
More often than not the bore isn't exactly on the centerline of the outside DIA, which can cause issues with devices such as strippers if they are not adjustable in the x-y direction.

lee545

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Re: Internal Air Stripper Prototype
« Reply #8 on: March 07, 2017, 11:33:50 AM »
The one "challenge" all these design have is that it relies heavily upon the concentricity of thread on the outside of the barrel to the bore centerline.
More often than not the bore isn't exactly on the centerline of the outside DIA, which can cause issues with devices such as strippers if they are not adjustable in the x-y direction.

For that reason, I over size the hole. That is what I did when I converted the one shown here for the core. 

rsterne

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Re: Internal Air Stripper Prototype
« Reply #9 on: March 07, 2017, 03:55:49 PM »
If you want to have the hole extremely close to the bore size, you pretty much have to have the cone position adjustable.... The same thing would go for any baffles, of course.... The usual solution is to make the hole bigger....

Bob
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Gerard

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Re: Internal Air Stripper Prototype
« Reply #10 on: March 07, 2017, 06:53:03 PM »
There can also be a problem of introducing instability by higher pressure air adjacent to any element after the muzzle. Laminar flow inconsistencies. Many have found that bore size minimum values for muzzle devices are limited by this factor, even in perfectly symmetrical systems. Going to a bore at least 25% larger than the projectile seems the practical lower limit. So for a 0.22" pellet for example, a bore of 0.28" seems safe so long as it is perfectly concentric to the bore. Larger if alignment if not perfect. Of course with very close placement relative to the muzzle this can shrink considerably and results can be tested to find the practical minimum for a given airgun and pellet, where group size is at least not made worse and ideally shrinks a bit.
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Rdsail

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Re: Internal Air Stripper Prototype
« Reply #11 on: March 11, 2017, 09:49:27 AM »
Here is an Stripper I was working on. More complicate. It designed it to be used with a shroud or 1/2 shroud.

Sandly, I have not made one yet to test out.

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