When I received the gun I filled it to 250 bar and the reg was set at 190. I reduced it to 150 bar.I shot it a few times to find that # 15 give the best speed of 850. I increased the reg pressure a little at a time while shooting every 5 bar increase a few shots. At 175bar I shot a 20 shot string. Hi 900 fps lo 888fps spread of 12 fps std of3.9. I stopped there. I am sure if I had more hybrids I could have got six more shots in to make two mag string before dropping to the reg pressure setting. I believe my reg gauge is reading 20 bar high...