On official vanilla server:

CR-61 Skorpion

1. finds a CR-61 magazine on the ground
2. open inventory management screen with TAB
3. place pouch into hands (which displays the contents in it)
4. drag magazine into the pouch onto the CR-61 Skorpion (blue highlighted box around item)
5. magazine will stay in the pouch but the CR-61 Skorpion will disappear from your inventory

Rice

1. find rice on ground
2. open inventory management screen with TAB
3. drag rice onto another item (e.g. pipsi) in inventory to swap places with it (blue highlighted box around item)
4. rice will replace pipsi in inventory but the can of pipsi will disappear, nowhere to be found