I've used the tape mod on my CP 2-piece for three years - arrow straight shots without any obvious unusual curve/spin... remember the tape only has to fold into the barrel just enough to keep the ball from rolling down the barrel. If you have a piece that is too long it could affect the ball (I guess)...
Educating duh masses - one ball at a time
Proudly playing for CSP (Ski Patrol)
Painball Club of Choctaw