A characteristic of cartridge brass is that it expands to fill the chamber and seal pressure at the instant of firing, but then it contracts slightly to permit extraction. If your fired shells are extracting without sticking, I see no good reason to polish the chambers aside from the fact that polished steel will not rust as easily as unpolished steel. But if you are cleaning and oiling your guns after use, then that isn't likely to be a real problem either.

Voting for anti-gun Democrats is dumber than giving treats to a dog that shits on a Persian Rug