Walther dominator 1250 regulator problem!!!!!!

[Sheharyar]

Hello,
I need help from the masters of regulators, 
I own a Walther 1250 Dominator .22cal in 40j , The regulator of my gun is not working properly,I did a chrony test today and the string was unbelieveable!!!
The velocity with 18.13 jsb pellets started with 870-875-890 and after a few more pellets it started increasing it went upto 956 and the started to come down back to normal range.Can someone help me on this? and what can I do now?

 

[BigTinBoat]

That reg should have bellville washers in it. I would (if you are confident) degas, disassemble, clean/inspect/replace parts, and reassemble.
It definitely sounds as though your reg is not regulating.

 

[Sheharyar]

Its not a problem for me to open it, I have already opened it and cleaned it thoroughly but no hope till now.

 

[scubajeeper]

Sounds like it is bleeding by, have you replaced the o rings?

 

[Sheharyar]

Yep. REPLACING ORINGS Solved the problem.