Possibly not relevant now, but 25 years ago I fired just a few 12 ga bird shot loads in my Winchester m 50 short stroke semi auto, neglected to clean right away, and while showing to a friend 2 weeks later discovered, to both our surprise, rust in the sliding chamber. Not much but enough to not trust again with out proof of non corrosive, which was described on the box.
Whom was it once said: <if you don't drink a country's water, don't shoot their ammo>. Apology for not proper notation.