User blog comment:PFC Arkalis/New Battleblog; Building BF3 from the gun out/@comment-83.70.77.110-20110812021344/@comment-28584497-20110815191934

Or they could revert back to the old method, where the extra bullets simply disappear with the discarded magazine.

That's what actually happens, given that soldiers usually don't have time to top up their magazines mid-firefight.