Hand, bullet loop on a holster, bandoleer, clip, magazine,
== == The part that holds the bullets in a revolver type pistol is called the "cylinder". In an automatic type pistol it's called a "magazine".
It means when someone in the army or who owns a gun has run out of bullets in his magazine (thing that holds the bullets) and has to replace the empty magazine with one that is full of bullets
The thing that is a sash like object that holds a katana is called an obi.
a clamp
The thing that holds dead man ashes is called an Urn I believe :)
A sheath.
Filament.
A bobbin or a Spool
Tomb or sarcophagus
sunglasses holder?
an easel
There is no such thing as the "study of bullets", except, perhaps, as a historian. However, one may study the effectsof bullets using "ballistics", and a person who does so for a living would be called a "ballistics expert"; someone who is trained to do such at a crime scene or laboratory may also be called a "forensics specialist", but the word "forensics" has nothing to do with bullets.