In a perfect world, IBO speeds should be measured at a 70 pound draw weight with a 30 inch AMO draw length and a 350 grain arrow. Nothing on the bowstring whatsoever.

AMO speeds are shot at a 60 pound draw weight, 30 inch draw length and a 540 grain arrow...but you really do not see AMO speed ratings published much anymore. This is most likely the result of folks wanting faster bows and enjoying the faster listed IBO speeds for any given bow. Fast bows sell.

At a 65 pound draw weight and a 28 inch draw length you should be able to get speeds of 260+ assuming you are willing to compromise on arrow weight a bit.