Recently I had my two Babolat PDs strung with Babolat Natural Gut (BT7) 16 gauge at 60 lbs. When I got them back I tested them with the iPhone "RacquetTune" ap and indeed they both registered at 60.2 lbs and I REALLY liked the way 60 lbs felt. Fast forward 30 days. Interesting fact... I've only hit with one of the two racquets for about 10 hours, but now BOTH register at 55 lbs. I can definitely feel the difference and much prefer the feel at 60 lbs. When I re-string I want to stick with full nat gut. So my 2 questions are: 1. If I re-string with 16G again should I string at 64-65 lbs to account for the 5 or so lbs of tension loss regardless of play? 2. If I decide to try 17G nat gut should the tension range be the same as 16G? Thanks!