Yes, I have access to a bowshop. I shoot a BowTech Guardian with a 29" draw, set at 70#. Yesterday I had it chrono'd at 317 fps. I had the arrow weighed on a digital scale at 390 gr.
That doesn't sound right. I'm not saying you're incorrect.....but it just doesn't sound right. Sounds awful fast for that setup.....maybe 20fps too fast. I could be mistaken, though.