Clean the chokes and threads if the gun has them. Keep the working parts cleaned and properly oiled or greased. Past the chamber and down to the threads or choke, shooting essentially cleans it with each shot. Take it down to bare metal and shoot a box of shells thru it, and as far as the barrel goes, you are back to where you started with a thin plastic coating. Know shooters who shot 10K plus rounds per year. Chokes, threads and chambers get cleaned fairly regularly, but the main barrel when it does get cleaned, will get a quick pass with a bronze brush or snake and some type of solvent. Done.
