FX Wildcat MK II .25 Seemed to Lose Power

Was benching it and practicing at 75 and 100 yds. Quite suddenly it SEEMED to be different. I thought the recoil was different and it didn't seem to smack the target with the same kind of power after I noticed this change. The chrono doesn't lie and it was shooting pretty consistently around 860 and was still on the regulator. At 25 and 50 it was pretty much the same but at 75 and 100 I could no longer tell where I was hitting the splatter bursts. I haven't done anything to the rifle except add a Koi Donny fl and it was on there when everything was 'right'. Any thoughts? No I wasn't smoking funny cigarettes even though it's now legal in Washington State.