Tonight I shot my second 300 in as many weeks with a GT1, finishing with a 740 set. Tonight was just odd, I had NO look in practice with anything, then went 14 in a row, then the shot evaporated again. This GT1 was drilled 60x55@3 3/4" P2 hole. For me the magic number for sum of angles on the GT1 seems to be 115 so far.
PS The first GT1 was drilled 75x40@4 1/4, no hole.