I'm sure there's some variables in Bows but If  I have 64'' 60@28 Mild R&D LB and shorten it in 1'' increments Roughly how many pounds will I gain per inch?

5 pounds by removing 1 inch from both ends.

Thanks Roy, So I cut 1'' off both ends I gain ten pounds correct?

No, 5 pound if you take one inch off both ends

Okey thanks

With that 60 pounder at least 5. Lighter bows prolly lose less.