yes some weapons don't have functionality, because code is not implemented and also you need to buy the weapons so warrock server know you have them.
that is my guess, that is why weapons do no damage.
only weapon working are the ones you bought, default weapons, winchester, smoke grenades, flash grenades, and maybe adrenaline (everyone in the room can see you used it but it does nothing), also they can see the parachute but it does nothing as well.