hello to all i am trying to help a friend get his crossbow shooting i am familiar with bows not cb so i have a few questions 1 do you paper tune cb's. 2. this is an older pse viper 150 with a metal looks like an older "flipper rest" can these be changed and if so where does a person locate these? Due to the rest we are having fletch contact with four fletched bolts can a person shoot fethers with cb's? I wopuld prefer to changfe the rest first. thanks