Knex Assault Crossbow

This is my assault crossbow. I tried to make it a mix between an assault rifle and a crossbow.
It has an extendable stock, a rachet trigger system (not my idea) and a sturdy bow at the front so you can add lots of power.

Pros: great range
very powerful (can kill someone with sharpened bullet)
comfortable
extendable stock to suit big and small people
has supports to make it less flimsy (two grey connectors and 1 white rod)

Cons: a bit flimsy, but nothing serious

tell me wwhat yu think. if there is something i can improve on let me no