check AOE - it probably is already corrected on G&P, but if not AOE could get it down about 15fps. Where abouts are you if TWA, can lend ya Element M105 or some other springs and chrono if ya need
Lozart gets way over the expected 300 using SHS M100 but he also uses all good bits too. Think they are about same for what its worth, maybe SHS retains tension better over time ?