Knex Bullpup True Bolt Action Gun (preview)

What's up? I made this gun lately. It isn't finished yet (as you can probably see by how it looks). It's true bolt action, and the magazine is behind the grip. It's pretty compact, but it needs a stock, which makes it a bit less. I need to figure out how to add one, but still keep it easy to cock. It is surprisingly comfortable (but it needs some stuff on the handle). I don't know how it shoots, as I don't have any big rubberbands. 
Tell me what you think, and maybe some help on the stock.
It's posted:
https://www.instructables.com/id/Knex-bullpup-bolt-action-gun-instructions/