As others have said on this thread, although we seem to be in a minority, but I clean after every stalk where a shot has been fired or after a zeroing session. Before I go out stalking I run a patch with a little bit of meths on it to clean out any oil etc and let it dry and my POI has never shifted. IMO 'dirt' in the barrel is not what is changing poi, it is getting rid of any oil or cleaning residue, which is exactly what meths does.If I cleaned every 40 shots I would not be cleaning from August till the following August, a fallow season. I once took this advice with a near new CZ, and in an old house that was not particularly damp, but obviously a little, lines appeared in the barrel within 6 weeks, that on closer inspection was surface pitting. It was very hard to stay on top of this and the rifle needed oiling almost daily just to control its spread and it did spread an eventually I sold the rifle to someone who planned to re-barrel it, I just did not trust it as the rust was immense.Carbon attracts water. If you leave your rifle barrel dirty, your rifles barrel will attract water out the air and water on a metal surface will cause rust. I have learnt the hard way and I would not wish it on anyone, that horrible feeling when you look down your barrel to see something other than a lovely clean rifling! Maybe I was unlucky but since my new regime of shoot and clean then swab out with meths I feel happy my poi is not moving and that my barres will not rust.
