Hw100 potential problem

[shropshire dan 467]

Evening all. I've just bought a HW100 thumbhole carbine in .177. 

If I fill it to 200 bar and leave it a hour or 2 stored barrel up in the safe the gauge goes down to around 160/170 bar. Never any lower, What could be wrong. Of course it could be me being a novice to pcp air rifles.

Any advice appreciated

[chendkoi 1]

Dan,check hammer spring is not overloaded/pre-loaded and sitting hard on valve.re-fill and leaved cocked to check after couple hours.Or your Regulator is creeping/maybe dirty inside.Or slight nick on one of your air-chamber main O rings located each end of cylinder,one gauge end other valve screw in end.Had similar on my FX verminator only dropped to 160bar,was damaged O ring on main tube.

[shropshire dan 467]

Cheers mate. I've just tried a different filling method. I've filled it from 150 to 200 with small bursts with a 10 second gap between bursts. It's smack on 200 bar at 18.45 

 

I only got it yesterday lol

[MickC 1,825]

Hot air expands so as it cools down it settles to a lower pressure,always best to fill pcp as slow as possible . Fill it slowly then just top up a touch at a time, give it time to settle till its at correct pressure you want it to be.

Edited June 3, 2018 by MickC

[shropshire dan 467]

Thanks Mick. Nearly 45mins after filling and she's still on 200 bar 

[Deker 3,478]

As Above, you will tend to find Dive shops commonly fill your Dive Bottle whilst in a bath of cold water to get the air in quicker and to full pressure!

Edited June 3, 2018 by Deker

[shropshire dan 467]

Cheers Deker.  Just checked and she's reading just below 200 psi so I'm well happy with that. 

 

Thanks again for your help gents.