I always (in civilian life) kept my mags brass up. For whatever reason, I had no problems ham-fisting my mag changes this way, and to my memory never dropped or soft stuck a mag. Cant ever remember having dirt in there either, but to be honest, IDPA and 3 gun matches I ever shot really didnt involve combat low crawls. So, why the downside? Because US Army standard is brass to the grass. I learned this on my third deployment (not sure how it got missed in the first two). This picture was taken immediately after a "React to ambush/react to contact" in a MOUT site. I effed up and lost count of rounds out, and ran dry. We were literally 8 feet away from the "insurgent" opfor on the opposite side of the CONEX box we had advanced to, and in my jacked up excited state, I went back to what I did in the civilian world during a speed reload. Click. The worse part, for me, was I failed to recognize that I had done it at all. I applied SPORTS (old school tap rack. Slapped the bottom of the magazine ( should have been clue 1 when it felt wrong), Pulled the charging handle, observed the chamber (Which should have been clue 2 seeing the bottom of the magazine and no brass feeding). released the charging handle as if everything was as it should, tapped the forward assist, and made the corner to engage the bad guys. Thats when my magazine fell out, and OPFOR ( who was actually a battle buddy of mine), literally looked on the ground, laughed, and "shot me in the face". This picture was on the wall at PTAE training two years later, when I ETSed and I will never forget that muscle memory is only as good as the consistency of the actions. I needed to spend a lot more time training my left hand to do the finger forward thing, and honestly still sometimes find myself slower for it. Thank god it was in training.... and yes, I spent about an hour that day after we were all done doing it the Army way..and a few more times before I went overseas