b-rice,

I think you mean IBO and AMO......which, incidentally, is now IBO and ATA....but that is on the QT, OK?

Sorry, I got carried away with all the letters there.

Seriously, AMO (now ATA) Archery Manufacturers Organization (Archery Trade Association) uses a 60 lb draw weight, 30 inch draw length and a 540 grain arrow for their speed rating. There is nothing on the bowstring besides some form of nockset.

IBO stands for International Bowhunters Association and their generally accepted speed rating is with a bow set at a 70 lb draw weight, 30 inch draw length and a 350 grain arrow. I say " generally accepted" because some manufacturers fudge on this one by using some less-than-scrupulous ways of getting more speed from their bows.

But I won' t go into that here.

Hope this helps.