Used to be bow manufacturers listed AMO & IBO Speeds. I hardly ever see AMO speeds listed any more.

Just for the record, my bow is rated 320-328 IBO. The birth certificate listed a speed of 320 fps. This is right in the ball park considering that the birth certificate rating is obtained with a brass nock set, Bowtech silencers and Vibrablocks installed. All of this together robs approx 6-8 fps from the bow.