Found an Ak 101 and took it in my hands (had Mosin on my back).
I already had some magazines stored in a Smersh backpack i was carying insde my normal backpack, so tried "r" to reload, but in my inventory the Ak showed not to contain a mag.
When i took an other item in my hands, and droped the Ak, i noticed the Ak then had a mag loaded.
I droped the Smersh backpack to check, and saw a clip was missing.
I picked it back up and draged and droped the clip from the Ak back in, but it still showed to be in the weapon.
Droping the gun and picking it back up fixed that.
I next loaded, droped and picked up the Ak agian, to try something else.
I put the clip from the gun into the Smersh, and then onto the ground.
Meaning the mag was actually loaded in the rifle at first, then moved to smersh (still shown in the rifle) and then draged and droped from the rifle to the ground, which made it disappear from the smersh.
Then i tried shooting the rifle with the (let's call it that way) ghost-mag loaded, and noticed i was able to shoot autofire forever, but without actually hitting anything, just animation and sounds for me (the ammo in the clip also didn't went down (30/30 all the time).
Trying to shoot with the mag actually loaded, but not shown, didn't work on the other hand.