Regulator Creep? Incorrect assembly or storage strategy?

[TotallyTortoise]

I have a Diana Stormrider in .177 that I installed an Altaros regulator in. My goal is to tune it way down to a nice level for my backyard.

Anyways, the initial installation seemed to work, but I noticed that while the gun sat, the regulator side manometer would creep up continually until it evened out at the chamber pressure. I pulled it out, planning on reseating it, and the o-ring tore on the chamber threads. Replaced it with a spare that came with it, lubed it up (30W silicone oil), and reseated it. Apart from regulating higher than the markings would have me believe it should be, it's still creeping. Over 24 hours it'll even up with the chamber pressure.

Once it dumps the initial overage, it'll shoot nice and even (last 9 shot spread this evening with JSB 10.3s averages 866 with an 8fps spread, set somewhere around 110bar) so it appears to work when it's working.

So, is there something to this installation I'm missing?
Is creep unavoidable with these push-in-tube type regulators?
Should I store the gun off reg and pump it up before shooting?
Or is storing at higher pressure, and a couple hot first shots, just the way this plays out?

For bonus points, are there regulated guns that won't creep like this?

Any education, wisdom, or such on the topic is welcome.

[tracker1955]

Sounds like air leaking past the seat, if new may need a little break-in time, if not new , seat face may need replaced or resurfaced.

[CableStop]

What kind of seal does it use?  Is it flat or ball bearing?

[Motorhead]

Yup ... seat itself not sealing OR an o-ring leaking from around the seat allowing bypass

[TotallyTortoise]

The seat is a bit smaller than the tube, so the sealing would be the face of the seal bottom against the bottom of the air chamber?

Should the chamber have been pristine when I opened it up? Mine had an accumulation of black oil around the valve end of the tube. I didn't have anything to get in there to clean it out and figured if it was there from the factory then maybe not a big deal. But maybe it's preventing the seal end from mating up properly?

[nervoustrigger]

Very unusual to have creep so severe that the output climbs all the way to the reservoir.  At least for the usual reason, which is a small imperfection in the valve seat.

Did you drill a hole to vent the middle chamber of the regulator, or does the design vent through the threads?  A sealed middle chamber can cause the symptom you’re having. 

[CableStop]

The seat is a bit smaller than the tube, so the sealing would be the face of the seal bottom against the bottom of the air chamber?

Should the chamber have been pristine when I opened it up? Mine had an accumulation of black oil around the valve end of the tube. I didn't have anything to get in there to clean it out and figured if it was there from the factory then maybe not a big deal. But maybe it's preventing the seal end from mating up properly?

I'd imagine it could cause problems.