Meh, I see what ur saying but.... for example, M9 magazines only hold 15 rounds.. chambering a round, dropping the magazine, loading 1 more spare round u happen to have, and re-inserting the magazine is not practical almost ever. Real world the only time u see a magazine+1 situation is a tactical reload, after uve shot at something and u want to be sure you have enough rounds for any further threats. It's taught (I know this because I teach it) but its not a load your going to be loaded with unless the shit hits the fan and ur engaged. Hell, 90% of the time the military is in a closed bolt load (Bolt forward, magazine in, nothing chambered). theirs a few exceptions of course, AF Cops carry one chambered and on fire for the M9 but still dont bother with the swapping for a fresh magazine.