I'm a noob at airsoft so don't take my cleaning procedure too seriously, but what I do for my CA M15A4 Rifle AEG is turn the hop-up setting all the way off, cut out strips of paper towel that are ~10mm in width and ~30mm in length (dimensions suggested in the CA manual), put those on the supplied cleaning rod, put two small drops of airsoft silicone oil on the towel to make it damp (but NEVER soaking wet), and run that in and out of my barrel, replacing the oiled strips as needed until no more visible residue gets on the cleaning strips. After that, I then usually run either one or two dry cleaning strips in the barrel (depending on how damp they get) to remove any excess silicone oil. I'd had good results so far doing that (with my performance staying intact), but experts please correct me if I'm doing it wrong.
Regarding tightbore barrels, what I've heard is that while 6.01mm barrels provide great accuracy, they require frequent cleaning and are prone to jamming due to their very tight tolerances. A 6.03mm tightbore barrel is the best, as it provides much-improved performance over a stock barrel (usually 6.08mm), while not jamming as easily as a 6.01mm barrel (although they still have to be cleaned).
My airsoft guns:
Classic Army M15A4 Sportline Rifle (SP003P-1)
Umarex Beretta 92FS Walmart Clearsoft Spring Pistol
Last edited by NS-Airsoft-Noob; January 27th, 2013 at 20:45..