I’ve got a 308.2 gram sand wedge head (MG TECH) that I want to add to my current set (TE Forged).  The gap wedge head weighs 291 grams.  Am I correct in assuming that I should trim an additional 1.22 inches from the tip – relative to the first step?  The shaft I am using is a DG R-300: identical to those in the irons.  I got the number by dividing the difference in grams by 7; then dividing that number by 2…to represent 1/2 inch units.  Any guidance would be appreciated.