Or is this an April Fools joke? Do NOT, under ANY circumstances, use pure oxygen in any PCP. The slightest bit of oil, and you WILL have a bomb go off in your face. This applies to any volatile or oxidizing gas. ONLY use compressed air or pure nitrogen. Yes, there are other INERT gases that people have used for various reasons, but hopefully they know what they're doing. There used to be a pic floating around the forums of a high end rifle that someone filled with oxygen. Don't know if the owner received his Darwin award posthumously or not, but the rifle looked like someone had used it for practice with a cutting torch, or like the left over pieces of some terrorist bomb. This is no joke, this kind of stupidity kills people. My apologies if I offended anyone.
Dave