Artemis P15 leaking air

Hi!

New to the forum need assistance with my Artemis P15 leaking air. I am assuming it's a bad o-ring somewhere but if anyone has advice on which ones to check first (most likely to fail) and instructions on how to take the gun apart to access the o-ring that would be most helpful.

I filled the gun to 250 bar 2 days ago and now it is at about 40 bar. I have done nothing with it but store it in the case. I noticed no leaking when I filled the gun, and it did not do this the first 3-4 times I have filled it, only the last 2 times. The first time I noticed the leak was after the gun had been sitting for about a month and figured it was normal for the air to slowly leak over that period of time. However 48 hours does not seem normal. Any help would be greatly appreciated.
You should never fill to 250 bar buddy only 200 and it's likely to be the top of the gun where you was filling it, get some warm soapy water and put it around where the air may be coming from! That a start, then the gun has to be degassed then twist the top off then you can change your o ring