I have an AI stock on my .223 and in the last few days I started to have a problem that the odd round would not chamber from the magazine but would hit the breech.
A quick cycle of the bolt cured this temporarily but it needed looking at.
Investigating it I found that the round was lifting early.
On closer inspection this was due to wear near the end of the guide allowing the round to clear the magazine about fifteen millimeters early and long before the bullet was in the chamber.
These are a plastic magazine, and there is no metal option to replace it, so the only fix is to replace the magazine.
This is after a few years and a few thousand rounds of use, and I'm not complaining about the life span of the magazine or its construction.