The CP 1 Piece is a larger bore barrel, so it will fit most any paint. It is also an agter market barrel, and because of this, more effort has been put into its manufatureing. Its microhoned uber good, so theres less friction and the ball is lined up happier. The barrel is also ported so theres less noise. U could have a better stock barrel of u stuck a piece of pvc pipe on the front of the gun