Daystate Wolverine .22 - groupings when filled to a pressure of 120-150 bar?

I'm still waiting for my 4500 psi CF cylinder and have been shooting the Wolverine using fills from a nitrogen cylinder at work which gives a maximum fill pressure of 150 bar. Accuracy is far from perfect with regular flyers. Is this the result of the low fill pressure or some other issue? SWP for my gun is 240 bar. How low can I go and still see optimal performance from the Wolverine?