I bought a DXT last year and have shot it quite a bit and love it. the other day I was playing around with different draw weights and thought I would max it out just to see the difference in the pull since I usually shoot about 64 lbs. Strangely enough, I tightened the limbs bolts till they won't tighten any more and I am only getting 66 lbs out of my 60-70lb limbs. When I bought it, I know it maxed out at 71lbs because I had to turn it down some. Does anyone know what would cause this?