RE: I.B.O. speed or Actual speed
As an example, my Reflex Grizzly set at 27" Draw length with a 340 gr arrow and 64 lbs draw weight shoots 257 fps. The IBO rating for that bow is 305 FPS. So deduct the 3" DL, the 6lbs Draw weight, the tube peep, the string leeches etc.... and I am pretty darn close to what it is advertised with all the deductions factored in.