Bare steel will be hard to take care of. Even if you clean it all the time and put oil on it there will always be the possibility of rust forming due to even slight condensation from temperature and humidity changes.
Also you will have to be concerned with the internal parts and the unexposed sides of the external parts.
If it is just one piece such as a compensator it will be easier, but then again why not get the one peice plated or coated and never have to worry about it?
It can't be all that expensive.
The Evil Captain Kirk