New pistol question

[ian.m.p]

I've just bought myself a s/h rohm twinmaster and I have a question for any owners out there. I have the owners manual with it and there is nothing in there about removing the air cylinder to refill it. I can see from the online diagrams that it is just screwed onto the pressure reducing valve but the cylinder appears very tightly screwed on and I don't want to force it. It is also difficult to get a grip on it as it is smooth and the barrel stops your hand getting an all round grip. I can't see any catch that is holding it tight. At present there is about 40psi (according to the inbuilt gauge), does it need to be totally empty to come off. Thanks in advance

[ian.m.p]

Got it, just needed tightening up then came off easy enough