Have an AKS74u with a half full mag.
Have a spare mag in a protector case in backpack.
Have spare stacks of 5.45 in said backpack
Detach AK mag and put it in inventory
Attempt to drag a stack of 5.45 to top off the mag (didn't work for me)
Empty the said mag (worked)
Attempt to drag a stack of 5.45 to load the now empty mag (worked for me)
Attempt to attach the mag to the 74U (didn't work for me)
Attempt to go in 1st person, to reload through actionmenu (didn't work for me)
Relog
Find both mags gone.
Cry.