No one in their right mind would ever be able to count their shots in the middle of a gun fight... You know how many rounds are in your gun, If you know you shot a whole lot of rounds, then do a tactical reload in a hurry... With retension, you never know if you need that ammo later, and a full mag/gun is better than a half empty mag/gun.... With practice anything can become instinctive.... Although, Todd Jarret on his 1,000 round torture test missed a couple of reloads...