Power Level Adjust/Constant velocity option

[MEHavey]

Just my big toe at this point......

I'm looking for accuracy at moderately high (not highest) power levels in .22, and the ability to adjust the power plantto that level so that bottle pressure variations are no longer a factor in shot strings until pressure drops below the regulator set point.

What says the the Forum on this reqm't with rifles at the <$700 range?

[melloroadman]

This is not what you asked for but it might help you . Marvin
http://www.pyramydair.com/blog/2008/12/comparing-regulated-and-unregulated.html
http://www.pyramydair.com/blog/2007/12/how-does-air-pressure-regulator-work.html

[ribbonstone]

Am thinking.

"Bottle" and "regulator".  Not clear on how much power is enough for your use...15 foot pounds? 20 foot pounds?  30? or how many shots per fill would be considered acceptable.

Do understand the desire for consistent velocity, which is what a regulator is supose to produce (and will if it's running right).

Just not sure of wich PCP's would offer those features.

[MEHavey]

Medium (~)25-30 ft-lbs for power.   (14.5gr Superdome@880-970fps, or  a 21.1gr Kodak retaining  730-800fps)

High-pressure air resovoir "bottle" goes on the gun having been filled from the SCUBA tank  
The "regulator" valve controls the final pressure going to the pellet regardless of bottle pressure.

The shots-per-bottle-fill not the issue at this stage, (although the 25-30 ft-lbs/shot & bottle size/pressure would be the limtiing factors.

[ribbonstone]

Well...these four QB conversions are not technically PCP's, although the tanks hold 3,000PSI.  Three or regulated to 850PSI and one is regulated to 1200PSI.  For as long as the bottle pressure is higher than the regulator's output, vel. don't vary more than 1 to 1 1/2% (unsorted, but good quality, pellets).

(click to enlarge)


The one on the far left is in .25cal and runs on 1200PSI output, puts 30.7gr. Kodiak's out at  685fps for about 32 foot pounds.  Small 13ci tank, running from 3000psi to 1500psi will give 35 shots with +/- of 8fps.


The short carbine (QB79 .22) was tuned for low speeds/long shot count. Runs on the same size tank, but with an 850psi output.  Dialed down to 575fps for 10.5foot pounds will give 80 shots of that same level of consistency running from 3000psi to 1000psi.

[melloroadman]

http://jdsairman.com/

[melloroadman]

http://www.airgunsofarizona.com/Daystate/DaystateRifles.htm Also some are putting regulated bottles on Air Force rifles as well . If you can do with out the regulated bottle you might look at some of the chrony readings I have listed . Also you might give Kirbby a P. M . and ask him to list the bottle  regulated rifles he knows of . Most that I am a ware of are like the Air Force line and regulate by striker spring tension adjustment . Marvin