I noticed a thread elsewhere that made a mention of a possibility of an AR USGI magazine’s feed lips being spread due to it being kept loaded.
I am curious if this indeed can be the case, as I like to keep a few magazines loaded and ready to go.
No, if the spring was powerful enough to put sufficient pressure on the loaded rounds to bend aluminium there would be enough force to push the rounds out of the magazine. Dropping mags bends and spreads feed lips, breaking the welds on the spine of the mag allows feedlips to spread. Magazines are consumable items. Use them till they are worn, then replace them.