I have 50 rounds or so. I think corrosive ammo was still being made in the early 50's,but don't know if any was 45ACP.
Back in the 60's we were still getting DCM ammo that was corrosive but that was 40's and 50's manufacture.We just went home and scubbed our 03's with hot soapy water and dried them off. No problems.
Areas with high humidity can typiaclly cause fine rusting and pittting if firearms are not properly cared for.
