Was wonder as I am fairly new to bow building if you take the same limbs off a let's say a 17 inch riser and put them on a 15 inch riser will it change the poundage and if so how much and what way?  Lonnie

Will raise the weight I would say in the 5 to 7 lb range.

Cory

If it increases 5-7 on a riser from 17 to 15 if the riser actually was 19 then you made a 15 riser for the same limbs would that then increase it 10-14 lbs?

Bow design will dictate that if you take 4 inches off the riser you are changing the design. You may be ok but if the bow has an 19 inch riser it probably  doesn't have a long working limb unless its a 66 plus inch bow and you will end up with a bow that stacks.