My rifle has a problem with what appears to be a tight chamber.  Rounds will not fully chamber.  I imagine the most likely remedy would be to ream the chamber.  

If you ream a tight chamber that had been chromed, how would that affect the overall corrosive protection that the original chromed chamber and bore provided?  I would think that if the chamber's chrome liining were removed, this would leave an interface between bare metal and the chromed throat and rifle bore.  Because chrome is a plating and can flake off, couldn't corrosive gases get underneath the chrome plating at this leading edge and leave residue that couldn't be cleaned, leading to corrosion?

I would be more concerned with messing up the chamber and having an unsuppported case explode.

Have you checked the headspace and determined that it is correct? What appears to be a tight chamber may be incorrect headspace.
Have you made a cast of the chamber and determined that it is out of spec?

wow this

You'd probably hammer your reamer, too.

Okay... Let's assume that head space is not the main issue, because rounds will not fully insert into the chamber.  Let's assume that I send rifle back to the importer and they ream the chamber, destroying the chrome lining.  Now... under that scenario, how will this affect corrosion under the remaininig chrome lining in the beginning of the throat or bore?

Not necessarily a valid assumption, sice insufficient headspace is the condition in whch the cartridge "will not fully insert into the chamber", causing the bolt to fail to lock up.
BTW: the last person who posted about such a problem had a portion of a ruptured cartridge in the chamber.

Let's assume that you never fire corrosively primed ammunition and always clean the rifle promptly and throughly. Let's further assume that you keep the rifle properly oiled at all times.
In that scenario, CORROSION will not be a problem.
Let's assime that you always fire corrosive ammuntion and never clean the rifle at all. Let's assume that you never oil the rifle.
In that scenario, damage from CORROSION is inevitable.

Aren't hypothetical questios fun?