I think your chrono is correct, they don't tend to be off by much at all. If I were going to check anything I would verify accuracy of draw weight scale and of course draw length. Your reading are almost too good LOL. You may have developed a quick release. shooting through a chrono does this. I had no idea I had perfected a quick release until it was pointed out to me. I was shooting about 15 fps faster than my buddies drawing the exact same length. A typical shooter shoots about 7 fps slower than if the bow were shot through a machine. A perfected release can add as much 10 or more fps to a machine shot bow.