Idahoelkinsrtuctor, If you add some turns on the cable you will increase the poundage on the bow, or you have to go to a longer string. I learned this trick when I was shooting an old XI legacy. I also had the limbs break and when they replaced them, couldn't get the poundage back. Now the bow was out of time, so when I played with the cables I added turns and my poundage was back.
The IBO rating is with a 360gr arrow at 60lbs at 30" draw. AMO rating is a 540gr arrow at 60lbs at 30" draw. Have fun shopping BareBack Jack!
Gselkhunter