I think the B96 was only made with one barrel length; after all it has a 5-shot magazine and intended to be used for timed/rapid-fire target shooting and a long barrel would tend to be a disadvantage. It would also be difficult to fit a shoulder stock since the CO2 capsule fits in the grip. This is purely speculation and I am no expert on this pistol although I have owned one for 15 years or so; a great little weapon which I would not consider selling!