How to script and CFrame a gun?

I want to know how to script and CFrame a gun similar to WIJ's/RAT's/FEARS's/TRA's guns (Some of their guns are different from each others so mostly WIJ's or TRA's will do),I don't want to use their free models because I intend to overcome the challenge without copying from models or sets.

I want a futuristic sort of gun similar the the groups listed above guns,ones that shoot lasers and this is optional but would really help if you told me how to make a cooldown script.