Fx Verminator Extreme leak

This is my first post here so firstly, Hi all. I'm a keen shooter from across the pond (UK). I mainly shoot centrefire rifles but I bought this verminator recently for a farm I shoot on where rimfire and centrefire rifles aren't suitable.

The verminator is a .30 and has been flawless until recently. Long story short, one of the outer orings on the regulator had failed so I replaced it and whilst doing that, noticed that there were only 7 washers on the reg. Not sure if that's normal as they're meant to work in pairs are they not? Regardless, I put a new oring on the reg, built it back up and checked velocity... 740fps with 44gr jsb's. It was running at 850fps before that... Anyhow, made a reg tester and the reg is set at 165 bar at the minute, again, not sure if that's correct or not but that's what it's at. Now my main issue (apart from it shooting like sh*t at the minute) is that I fill it to 250bar and over two hours it looses around 40 bar and then it'll lose the rest of its air over the next few days. I can't hear any air leaking out from anywhere, soapy water has found nothing so where the hell would you go with it? I emailed FX two weeks ago and still awaiting a reply so I thought I'd ask you knowledgeable lot. The UK based forums are pretty useless as the majority of us are limited to 12ft/lbs and the guns are riddled with anti tamper so no one really has a clue what they're on about.



Any help is greatly appreciated. 
 
I would get in there again and check the reg orings or maybe even before that use some soapy water and find the leak. Or a thin tube and put it to your ear and probe around you might hear it.

I would venture to guess it had the proper amount of belleville washers and would take the extra you put in back out.

Huma makes a great reg, if you ever want to upgrade i put one in my Royale 500 and Boss and havent looked back. (Same breech block as your gun)

165 sounds about right for .30 cal with a pretty small plenum.
 
Thanks for the reply Glem. I've used the soapy water and there's bugger all in the way of bubbles. I've got an automotive stethoscope at work, never thought of trying that out. I didn't put an extra one on, I just noticed that there were only 7 and not eight. I have seen the huma and thought that the Boss reg looked the same. Are they really that much better? If I can't get anywhere with this setup I think I'll order one. I've made another observation as well; if I fill it to 250 and then leave it for 20 so minutes, the first shot is around 400fps and then the second back up to 700ish but still not the 850 it was at so I'm thinking that it's leaking on the output side of the reg or after. Oh and another quick question, can the hammer spring be wound all the way in or will it hold the valve open? Got it at the factory setting still currently.