We are all in agreement that constant shooting and/or excessive compression-contraction of magazine springs will cause the springs to wear out quicker than if the magazine is left continually loaded or unloaded. What's not agreed is whether a fully-loaded magazine spring will gradually weaken over time. My opinion is that if a fully-loaded magazine will suffer no deterioration in its reliability (the position of one camp) then certainly downloading by one or two rounds won't cause any deterioration either. I recently began downloading my magazines by one round and leave them in that condition for at least several months at a time because I haven't had the chance to go to the range in that interim. After those several months pass I unload that magazine and use a different magazine. I know some will claim I'm actually causing more wear to the magazine spring by doing this but like a lot of firearms issues there's a difference of opinion. Over the past seven years since I became interested in firearms I've changed my opinions on a number of these issues and expect there will be other opinions that change in the future.