Ty for the tipp, but I don't rly get it....if I press "r" it chambers a new bullet (which only "clicks"), but the one which pops out is gone....not in inventory, not on the ground.....so I have to hold "r" to get the ammo back at least?

Also see -> https://feedback.bistudio.com/T130999 he desribed pretty much the same...

Same here....lost an MP5 & an AKM this way.....in only one day....reported it too.....sucks rly hard to throw away a good wpn in perfect condition for nothing...and all the ammo :/