Nerf Big Bad Bow arrow to Elite darts converter

Bought a used Big Bad Bow but can't find the arrow for it. Thus decided to mod it to shoot Elite darts.

I want it to 'looks' as original as possible, so using CPVC barrel and/or cutting the nozzle is out of the question. Instead I've made this simple 'inserts' converter for the nozzle so it can fires elite darts, and can also be removed to fires arrows. Furthermore, it goes all the way through the nozzle until the parts that stop the plunger, thus removing more dead space.

You need to remo