Reply To: Quick ? for those who have experienced regulator creep

Forums PCP Airguns Quick ? for those who have experienced regulator creep Reply To: Quick ? for those who have experienced regulator creep

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nervoustrig
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Centercut, I don’t  know that we disagree, we just aren't laying out all the specifics.  The devil is in the details.  I touched on it in the linked thread…the extent to which a particular gun is insensitive to pressure variation (creep) has to do with the myriad of parameters that affects an unregulated PCP's ability to self-regulate over a wide pressure range.  In other words, there is a natural bell curve that centers on a particular pressure, and for a couple hundred PSI in either direction it will hold the same velocity (tight ES).  However when we tune a regulated PCP, we often do not know where that optimum pressure is.  Instead we usually pick a velocity we want and then go for it, using whatever knobs and dials are at our disposal.  So it's no surprise when the gun isn't quite so agnostic to creep, especially in cases where a gun is hot-rodded to much higher FPE.

In terms of the example you gave, I think that's a perfectly valid point.  Changing the setpoint even 10 bar may well alter the velocity and POI.  However the extent to which it does all goes back to that natural balance of HST, hammer weight, stroke, porting, and valve return spring.  If the 10 bars lies within the gun's natural bell curve of self-regulation, it will make no difference.  If it doesn't, then the velocity and POI will change.