Works fine for me.
Replaces the weapon in hand with the new weapon, if you already have one of those weapons in another slot it empties your hands and replaces the existing one because you can't have two of the same weapon and you chose to replace it.
Exactly how it is supposed to work.
Primary Desktop:
i7 7700,k NV1070 8GB, 16GB 3200mhz memory, 1x 2TB Hybrid, Win10.
Secondary Desktop:
i5 4760k, NV960 2GB, 16GB 2333mhz memory, 1x 2TB Hybrid, Win10.
Primary Laptop:
i5, NV1050 4GB, 8GB memory, 1x 1TB HDD, Win10.
Secondary Laptop:
i3, Intel 4000 series graphics, 6GB memory, 1x 500gb HDD, Win8.1.