Hi guys. Bought a new Artemis p15 .22 2 month ago. Fps was 850 steady on 30 shots jsb 18.13. From 230 to 130 bar. Did around 1500 pellets so far. 2 days ago my POI dropped so I checked the chrono and fps was 790/ 800. The Hammer spring reg is turned clockwise to the maximum from factory...