DayZ field wiki · Gear
Magazines
Empty is not a jam
Short answer
Load them before the door. Counting is a friendship. See jam-clear.
Also: mags
How it works
Mags hold rounds. They have condition. Filling them takes time you do not have in a stairwell.
What to do
Fill in a bush, not a window.
Don't
Don't dump empty mags as clutter into the only pouch.