I was raised in western Mo, lots of humidity. If we didn't wipe our guns off with a lightly oiled rag when we came in from hunting on Sat afternoon there were rusty fingerprints on them the next morning when we got ready to go out again for the day.
When we were done for the day or weekend, everything got a thourough cleaning, inside & out and was wiped down with a lightly oiled sheep skin before they were put away. This was done everytime we had anything out and shot it.
I have lived in Colorado for the past 40 yrs and this country has ruined me as far as cleaning guns is concerned. I almost never do! The dry climate removes almost all problems including to have to clean good after shooting corrosive ammo. I generally clean my shooting stock a couple of times a year, mostly just for the hell of it.
I have a MAC 10 that I bought new in 1976 and have done my best to abuse it just to see how good they really are - Let me tell you, they are as good as any gun can be! I have around 9 or 10K thru it and untill a trip to Okla a couple of years ago it had Never had a cleaning rod in the bbl or a drop of oil put on it. Back there because of the humidity it got disassembled and cleaned good. First time I've had it apart since I first got it.
The only concession to cleaning the MAC was that I always fired the last 1 or 2 rds of the day with non corrosive ammo. Everything else I have shot has been corrosive. Actually, I usualy do this with most of my guns.
I know that many will not buy/shoot corrosive ammo because of the problems it causes. I am very fortunate to live where I do. When I go to a gun show I look for the older WW 2 vintage ammo because it is always cheaper than the newer NC ammo. My 98k, Garand, MP 40, Sten, Thompson and BAR eat the corrosive just fine AND I don't have to clean them at the end of the day - even the gas operated ones.
Sarge