The ultramags IBO rating is at 305. That is based on a 70lb, 30" draw. To give you an idea, I'm shooting a Vipertec which is rated at 300 IBO. I'm shooting 28" draw and 63lbs. I'm shooting Vapor 4000's and I'm getting a very consistent 250 with it. I would assume at 70 pounds I would pick up the speed to somewhere in the ballpark around 255-260.