We have had many requests for a .40 to 9mm conversion barrel. For multiple models. We R&D a VP40 to 9mm with great success. To keep it an absolute drop in +p ammo had to be used to overcome the spring. Other than that the 9mm mags locked in and it shot without any issues. Imagine your VP40 being able to shoot 357 sig and 9mm with a few swap outs. Is there any interest in something like this?