From what I have observed, I do believe ammo lasts much longer than we used to think it did. I just recently had a old model 36 returned to me that I had purchased for my Mother to have as personal protection. I do not remember just when I bought this for her, but think it was early 60s time. I bought two boxes of ammo, both non +P, and over the course of a week or so, we shot up one box. I then cleaned and oiled down the pistol, loaded it with the first five rounds of the second box, and after carefully wiping down, replaced it in the box, gave it to her. At least 45 years later, when I next saw the pistol, it still had the same five rounds, along with the box of 45 . I had possibly over oiled the pistol, as I figured it would not be handled much, so was interested, and while all of the rounds in the chamber did fire, they might have been a little weak.
Another incident, traded for an old Rossi small frame, copy of the #36, and the old Gent who owned it did not remember when he had traded for it, but it had to have been mid 50s or so. Again, had been loaded with five rounds of a brand I had not seen in many years, however he had been a textile loom fixer, so when he thought of it, shot it with some sort of airosol lube, such as Wd40. Four of those rounds fired, again, a bit weak, but the fresh rounds from a box did great. I have seen local LEO come into the shop, grab a can of WD 40, spray down their semi auto, wipe it and replace in holster, without removing the magazine. When I have mentioned possiblility of oil getting into rounds, I have been told, Never happens. I'm of the opinion, every six months, I will fire my carry rounds, clean the pistol, and replace with fresh, but that is just me, semi auto or wheel gun.
