How can ammunition be identified?

Ammunition can be identified primarily by examining the caliber or gauge found on the cartridge's headstamp. The headstamp is a marking typically located on the base of the cartridge case, and it provides critical information about the cartridge, including the manufacturer, caliber, and sometimes the year of manufacture. This information is essential for identifying the ammunition type, ensuring compatibility with firearms, and for safety considerations.

Labeling on the box can provide useful information, but it is less reliable for identifying the ammunition once it is out of its packaging. Weighing the cartridge can give indications about its components but does not provide specific identification regarding the caliber or type. Similarly, the assembled length of the bullet may indicate its purpose or performance, but it does not uniquely identify the ammunition, as various rounds can share similar lengths while differing in caliber or design. Thus, headstamps remain the most definitive method for identifying ammunition.