So, what I have in mind, is for a disposable rocket launcher, it is made for penetrating the armor of tanks and it looks like

And when you take off the cover, it turns into this (those small black and white things are sights. btw please no ironsights or any sights at all)
warning: slight pagestretch below
So, for taking off the cover, it would be either: Every time you equip it, the animation would take off the cover (to prevent rocketnoobs from taking it out and quickly firing) OR When you first equip it, you have to click to take the cover off and it would stay taken off once you first clicked it.
The Specs:
When you shoot the rocket, the launcher would instantly disappear from your inventory. The rocket itself would do 100 damage on contact, and have a small (5-7 brick radius) splash damage range. The rocket will do at least 50 damage at the farthest splash damage range. (And if you could code this) It would destroy vehicles on contact (this does not raise the player damage).
That's it (I think).
EDIT: Oh, and It would also have a backblast that would do idk 20-30 damage? It's kinda up to the coder.