I didn't find anything about this bug in forums (using via search-button) or then I was just blind. This is actually little similar to some guns getting jammed when picking up some weapons. However, this one is quite different;

I had AK as my primary. I shot few clips and during middle of reloading (when it was done about halfway of reloading), it jammed and I couldn't do anything with it afterwards, no matter what I tried to do. I didn't pick it up as I said, it was my primary and I didn't tap / press throw/nade button at all. Anyone of you know what might be cause of this?